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A watermark on a photo is a means to protect copyrights on a photo. Often this is a translucent lettering or emblem.

Why do I need a watermark on a photo

Let's say you are a photographer. Take cool pictures, upload them to. Some people will want to embed a photo in their content. You worked hard and looked for the right angle, spent a lot of effort. And you do not want your material to be used by third-party people for no reason. So that they don't just take and download the photo, the photo bank can add your unique logo to the photo. And the person will either have to pay for a photo without a watermark, or be content with an image, on top of which your name is superimposed.

The name of the watermark is not accidental, it contains the very essence of the phenomenon. By default, according to generally accepted standards, it should be translucent, barely visible, like circles on water. The sign itself should not attract heightened attention, because the image itself is important, and not its authorship. A properly executed watermark is a subtle and subtle but distinct attribution icon.

Who needs watermarks

• These tags are specially designed to protect the image from theft. Even if the author does not bother too much with protection, but simply sets the name of his site in the corner, then this can stop those who put the copy-paste process on the stream.
• On the other hand, all users who still download and put photos and pictures on their own resources, in fact, will make the author free advertising. Thus, many photographers of recent years have been promoted and become famous.
• Branding plays an important role, that is, the distribution of a certain trademark through its logo in images. Many consider this to be the biggest advantage of watermarks, as it is much more useful than protection against theft. Pictures with a logo, especially if they are different, originality, unusualness or special style and beauty, quickly go online, popularizing your brand (company, company, name, etc.).

In addition, business people do not have to worry about increasing sales, since when copying, the personal brand will automatically be promoted and popularized. No one can just upload your drawing or photo and use it for their own purposes, for example, to create collages, prints or advertisements.

Cons of applying Watermark

We will describe below how to apply a watermark on a photo, but now it is worth discussing the question of why many refuse to use it. There are special reasons for this, which it would not hurt to consider in advance.

• Many people believe that the fundamental and main disadvantage of watermarks is that the image is not perceived as whole and harmoniously, since the mark distracts all the user's attention to itself. In many cases, it also gives the picture the look of consumer goods, but here it all depends on the author's sense of style and taste. There are many examples of the fact that the correct application of Watermark only adorned photographic materials.
• The protective functions of such signs are rather vague and cannot be called a real "weapon" in the fight against content thieves. It is worth agreeing that the name of the site in the corner will in no way stop those who decided to acquire just your picture. Yes, an attacker will have to spend time removing the stamp, or maybe just cropping the photo, but this will take no more than a few minutes.
• Watermarks applied to images do not and cannot bear any legal protection, since it is quite possible to find hundreds of thousands of "clean" images on the Internet and mark them with your own watermarks. Of course, in the case of an author's photography, justice can be achieved, but you will have to provide more weighty evidence than the captions on the pictures.
• One of the factors that prompts people to abandon watermarking is a significant deterioration in sharing, that is, the use of images in third-party publications, but with backlinks to the source.

And users social networks, for example, the notorious Pinterest or Instagram are less willing to share photos that have watermarks. This means a decrease in the popularity of a page or blog, for a business - a decrease in gross sales and the like, unpleasant things.

Ways to apply watermarks

Watermark

The English-language site is quite descriptive and also intuitively easy to use. To use the resource, you do not need to sit down to study foreign languages, it will not be difficult to figure it out.

• Upload the image to the page.
• Download watermark.
• Align both images.

The logo can be edited, for example, change the transparency of the image, its size, position and even color. In one click, the sign is applied to the image, and then the image is saved to your device. It should be remembered that you need to download the photo right away, because the period of its storage on the resource is only a week.

Adobe photoshop

An excellent program for applying watermarks on photos, this is everyone's favorite Adobe Photoshop, which at times, like fire, are afraid of beginners. In fact, it is not at all necessary to be able to use all the functions in order to equip an image with Watermark, basic knowledge and skills is enough.

• Install the dedicated Adobe Watermark panel application.
• Choose the watermark you like best for all images.
• Adjust the available settings as you see fit (size, transparency, number and position of characters, and so on).
• Select the quality for saving (web, jpeg, png).

Moreover, the program has the ability to view previews, as well as put signs on a large number of pictures at a time.

From all of the above, we can confidently conclude that the issue of applying or rejecting watermarks is far from unambiguous. Basically, the decision will directly depend on the goals pursued, as well as the site where all this will be located. For example, if we talk about online stores or other type of trading sites on the network, then one cannot do without the use of watermarks. After all, having spent a lot of time and effort on creating unique photos, I want them to be seen exclusively on your website.

If we talk about the sites of professional designers, photographers or stylists, then such "dyeing" in the form of a logo or name can spoil the whole impression of a photo, picture, spoil the correct perception of the atmosphere of the image. Many suggest placing analogs of low quality and small size on such resources so that competitors cannot also use them.

Many of you have already come across the presence of a watermark on the image. Initially, the signature on the photo was made only for reasons of the author's fame, but nowadays, when it became possible to widely use other people's images without any notification and mention of the author, another practice began to appear - to leave a watermark instead of a signature, and preferably on all images. If they are already borrowing, then let the users at least know where.

Since it is not always convenient to use a full-fledged computer with the appropriate software on vacation or on a trip, in this article I will offer you a service that will allow you to create an image with a watermark even from a mobile or tablet!

Watermarking an Image in Three Steps

1. Load the image (Manage Photo (s))

Formats allowed jpg, jpeg, png, gif, bmp, tif, tiff to make the photo smaller 500Kb... Multiple files can be uploaded.

2. Create a watermark (Add Watermark)

And then the expanse! You can either upload your own image - the loading conditions are the same as with the main, background part (the same formats, less than 500 Kb), or text, which is remarkable - there are many options for formatting it: text input, about 60 fonts to choose from, size, color, slant, transparency.

The result can always be seen in the block to the right. The update takes 1-2 seconds.

3. Save your image! (Process Photo)

Everything about everything, as a rule, takes less than a minute of time. Then choose how to download the image (the watermark is available separately).

Service link

www.watermark.ws- service for applying watermarks to images on-line.

Thank you for the attention! And I wish your site only conscientious visitors!)

INTRODUCTION

Chapter 1. TECHNOLOGICAL PROTECTION

Water marks
Ways to simulate watermarks
Security threads
Simulated security threads
Protective fibers
Imitation protective fibers
Optically variable inks
Optically variable paint imitations
Holographic protection
The composition of the paper and its optical properties
Simulate paper properties

Chapter 2. PHYSICAL AND CHEMICAL PROTECTION

Luminescent protection
Simulated luminescent protection
Infrared protection
Attempts to imitate infrared protection
Magnetic shielding
Simulated magnetic protection
Other types of protection

Chapter 3. POLYGRAPHIC PROTECTION

Letterpress printing
Flat print
Gravure printing
Screen printing
Special types of printing
Other methods of printing protection
Microprinting
Attempts to simulate microprinting
Composite images
Simulating merged images
Hidden images
Imitation of methods of polygraphic protection

INTRODUCTION

In everyday life, each person constantly has to deal with various documents. For most of us, the word "document" evokes quite definite associations: it is a kind of "official" paper with text, signatures, stamps and other details - for example, a passport. In fact, much more often we come across other types of documents, which, although they do not completely correspond to this idea, play an equally important role in our life.

So, when making purchases, we are dealing with money, in particular, with paper banknotes - Russian or foreign. When buying tobacco or alcohol, we see excise (special) stamps on the products. When exchanging money at an exchange office, we present a passport or other identity document. Drivers of vehicles, among other things, when communicating with police officers, show their registration certificates, coupons and other documents. Not to mention promissory notes, stocks and other securities that are increasingly common to us every day.

At the same time, usually unconsciously, each of us solves a problem for himself - he is holding an authentic or fake document in his hands. And for this, voluntarily or involuntarily, a person has to find out how much this document corresponds to his idea of ​​authenticity: what has signs of the present in it, and what may indicate a fake.

How do we solve this issue for ourselves?

The fact is that each document is provided with a certain set of means, usually called protection.

Document protection is a set of features implemented using visual characteristics and special technologies and allowing to unambiguously establish the authenticity of a document.

At the same time, technology is usually understood as a set of processes, equipment and materials that provide a specific effect, observed visually or with the use of special devices.

In general, the purpose of security is to create a set of features designed to identify a document as genuine.

In this regard, one should clearly distinguish between the means of protection that determine the authenticity of the document: a) for the consumer, b) for a specialist.

For the consumer, the most important are those features that make it possible to determine the authenticity of a document quickly, simply and without the use of special means (devices, observation conditions and techniques).

An example of such protection is a paper watermark. On money, for example, it is visible in the light - it is enough to raise the banknote towards the light (Fig. 1).

Rice. 1. Watermark paper banknote
with a denomination of 100 rubles, issue of 1997.

The specialist needs more characteristics that provide - with a general external similarity - confirmation of authenticity in special conditions: the presence of special devices and special knowledge.

An example of such protection is infrared protection of special brands. To determine such protection, special devices are needed; if any, the observed pattern (Fig. 2) serves as one of the reliable evidence of the document's authenticity for a specialist.

Rice. 2. Infrared protection of special brands
"Strong alcoholic drinks".

In any case, the protection of a document is a complex of means, and the presence of one or more of them separately cannot serve as a basis for resolving the issue of authenticity. Only the entire set of protective equipment can confirm the authenticity of the document.

In addition, protection - as the name implies - is intended to make it difficult or impossible to falsify a document.

Usually, speaking about protection, it is customary to distinguish three of its types: technological, physical and chemical and printing. Although this division is rather arbitrary, most of the means of protection, as a rule, fit well into this classification.

The following is a description of all the listed species with their varieties, as well as known from practice methods of forgery. Here it is appropriate to immediately make a reservation: in the future, we will talk mainly about imitation of means of protection, and only in some cases - about their reproduction.

Under imitation means such techniques that ensure the receipt in counterfeits of effects similar to genuine documents (perceived visually or with the help of devices), but achieved using other (not original) technologies, that is, in ways different from those used for security in genuine documents.

Unlike imitation, reproduction- This is a repetition in one way or another of the original protective technologies. Usually, in practice, such forgeries are classified as "super". This is due to the fact that security means in genuine documents are made using complex, often unique technologies, the reproduction of which requires special equipment, materials and special knowledge.

TECHNOLOGICAL PROTECTION

WATER MARKS Ways to simulate watermarks
SECURITY THREADS Simulated security threads
PROTECTIVE FIBERS Imitation of protective fibers
OPTICALLY VARIABLE PAINTS Optically variable ink imitations
HOLOGRAPHIC PROTECTION
PAPER COMPOSITION AND ITS OPTICAL PROPERTIES Imitation of paper properties

Chapter 1

It is customary to call technological protection a complex of features found when studying the materials that make up a document, and, first of all, its substrate (most often, it is paper).

This type of protection includes:

• paper watermarks; security threads (stripes);
• protective fibers;
• the composition of the paper and its optical properties; optical properties of paints; holographic images.

WATER MARKS

Watermarks are images formed during the manufacture of paper due to local changes in its thickness and observed in transmission. This is the most common and reliable form of paper protection. At the same time, this is a rather complicated type of protection, since its receipt requires the presence of special technological equipment (paper machine).

Watermarks obtained during the manufacture of paper are usually called natural (true). Such watermarks are characterized by a change in the thickness of the paper at the location of the image.

All currently known methods for imitating watermarks are based on various methods of changing the optical density of the finished paper.

Depending on the number of visually observed gradations (tones, densities) that differ from the density (background) of the paper, watermarks are usually divided into:

• plain (light or dark);
• two-tone;
• multi-tone (halftone);
• combined, combining elements of the previous types.

Monochromatic watermarks are images that are dark or light in relation to the background of the paper, visible in transmission. A typical example of a solid color (dark) watermark is a travel document (train ticket) paper watermark. A light monochromatic watermark can be seen, for example, on Ukrainian hryvnias of 1992 issue (Fig. 3).

Dual tone watermarks contain both lighter and darker images in relation to the background of the paper. They are found on banknotes (denomination designations in Russian rubles, Fig. 4), and on special stamps ("Strong alcoholic drinks", Fig. 5), and on identity documents (passport of a citizen of the USSR, Fig. 6).

Rice. 4. Two-tone watermark of paper banknotes
with a denomination of 10 rubles in 1997.

Rice. 5. Two-tone paper watermark
special brands "Strong alcoholic drinks".

Rice. 6. Two-tone paper watermark
passports of a citizen of the USSR.

The watermarks shown in Figures 5 and 6, by the nature of their location, refer to marks along the field (general), that is, their pattern (pattern) is repeated many times over the entire observed field.

In addition, there are local watermarks, the image of which is located in a certain place on a banknote or page of a document.

As a rule, local watermarks are multi-tone - their images contain smooth changes in density. More often they are called halftone or portrait, since such signs are most common in the form of portraits of personalities - persons depicted on banknotes (stamps of Germany, Fig. 7).

Rice. 7. Halftone (portrait) watermark
on the banknote of 200 German marks.

In the same illustration, you can see a combined watermark that combines multi- and monochromatic (portrait and denomination).

A type of local is a repeating (stripe) watermark. It represents repetitive - often vertically - identical images. It is usually found in the form of portraits on banknotes (crowns of Sweden, Norway).

Ways to simulate watermarks

Practice shows that most often watermarks are imitated in the following ways:

overprint (drawing);

impregnation with fatty substances; embossing (pressing);

mechanical scraping.

The most common way is to simulate a watermark by overprinting (painting). This method is usually used to simulate single-tone dark, two-tone and multi-tone characters. Overprinting is usually done with a dye that matches the shade of the paper used (most often white ink).

Such imitation is usually easiest to detect in ultraviolet rays (UVL). When the UVL of the document is illuminated, the overprinted image looks dark on a lighter paper background (Fig. 8, a). Watermarks imitated in this way, when viewed in transmission, usually have clear boundaries (Fig. 8, b), since most often the paint is applied from a letterpress (cliche) or flat print, less often - by drawing with a pen or brush. When imitating a watermark from a rasterized printing plate, it is possible to transfer halftones of an image of a multi-tone watermark - for example, a portrait (Fig. 9).

In addition, the presence of an overprint can be determined in diffuse and oblique lighting, while the image of the simulated watermark will differ from the background of the paper by the nature of the reflection - gloss (Fig. 10).

Rice. 8. Watermark imitated by overprinting from a line form:
a - under ultraviolet rays;
b - to the light.

Rice. 9. Simulation of a halftone watermark,
made from raster form:
a - to the light; b - in the UVL.

Rice. 10. View of the overprinted "watermark"
sign "in oblique light.

Impregnation is usually used to imitate light, solid color watermarks. For such imitation, waxy substances or oil-containing compositions are used. In this case, an image of the watermark is applied to the substrate (paper), either from some printing plate, or by hand, using a tool such as a pen. For simulations performed in this way, a somewhat "blurry" picture is characteristic, observed in the light. The longer a document with this “watermark” is in circulation, the more blurred the image. Nowadays, fakes of this type are becoming less and less common.

Watermarks are often imitated by embossing. In this case, local compaction of the paper occurs in places corresponding to the light areas of the watermark. Typically, these simulations have little contrast to the background of the paper when viewed in transmitted light. But they are usually very visible in oblique lighting. The salient features of an embossed watermark are shown in Fig. eleven.

Rice. 11. This is what embossed watermarks look like:
a - when observed in the light;
b - in oblique lighting.

Quite unusual and rare is the method of imitating watermarks by scraping. The method is based on a mechanical change (decrease) in the thickness of the paper layer. In this way, light monochromatic watermarks are quite successfully imitated. Harder to get halftone watermarks by scraping. This requires removing part of the paper layer by hand to different depths using a cutting tool (knife, scalpel) or an abrasive material - fine sandpaper, a hard eraser.

Depending on the circulation and the qualifications of the performer, such a fake can be made either simply by hand, or using some kind of template (stencil). An example of simulating a watermark using this method is shown in Fig. 12. The figure shows that when viewed in transmission, such a "watermark" looks rather rough, and in oblique light, local violations of the surface finish of the paper are clearly visible.

Rice. 12. Imitation of a watermark by mechanical scraping:
a - view to the skylight; b - in oblique lighting.

PROTECTIVE THREADS

A security thread is a narrow (1-2 mm wide) strip of polymer material embedded in paper during its manufacture. When studying a document, security threads are found in transmitted, reflected diffuse and oblique lighting.

In appearance, security threads are quite diverse, however, two main types can be distinguished:

diving (fenestrated) threads, fragmentarily protruding onto the surface of one of the sides of the paper (usually in the form of a dotted line of several equal segments).

The hidden threads are visible only in the light. They, in turn, are subdivided into the following options:

metallized solid - observed in the form of an opaque strip (Fig. 13);

metallized with text - in the form of an opaque strip with transparent (light) letters and numbers;

transparent with text - a semitransparent strip with opaque (dark) characters or images (Fig. 14).

Metallized filaments can also be magnetic. Transparent filaments sometimes glow with some color when viewed in ultraviolet rays. These properties can manifest themselves both along the entire length of the thread, and locally (Fig. 15).

Rice. 13. Solid metallized security thread
(AMD 1000 in Armenia).

Rice. 14. Transparent security thread with text
and images ($ 50).

a - along the entire length (20 US dollars);
b - local (10 rubles).

Diving threads can be observed in transmitted and reflected light. As a rule, they are metallized; therefore, in reflected light on one of the sides of the document, the thread is found in the form of a dotted line of shiny segments of equal length, and in transmission, such a thread is a continuous strip.

According to their design, diving threads are divided into the following types:

solid - no texts or images are observed in the transmission (Fig. 16);

with transparent text (fig. 17);

with a holographic effect, that is, having a "rainbow" coating (Fig. 18).

Stripes with different optical densities are visible.

a - view to the skylight; b - a piece of thread with applied
over it with an image.

There are also diving filaments that luminesce in UV rays.

It should be noted that when studying in transmitted light at the site of the diving thread, local changes in the optical density of the paper are found in the form of dark stripes perpendicular to the thread, and these stripes are located between the segments of the thread that emerge on the surface (Fig. 16).

It should also be borne in mind that the images on the document, regardless of the method of application, are located on top of the diving thread (Fig. 17b).

In oblique light, in the areas where security threads of all types are located, a local thickening of the paper is observed, which looks like a relief strip (Fig. 19).

Rice. 18. Holographic effect on threads
(CITICORP travelers checks).

Simulated security threads

There are four main ways to simulate security threads:

overprint;

additional drawing;

sticker;

Various combinations of these methods are also possible.

Overprinting is more often used to imitate hidden threads. In this case, the following options are possible.

The simplest one is to print the text (image) on the thread with white ink on one of the outer sides of the document or on the inner side of one of the sheets (for documents glued from two sheets). At the same time, unlike genuine documents, the boundaries of the thread itself are not visible in transmitted light, and a relief overprinted image is observed in oblique light. In UV light, this overprint usually appears as a dark image on a light background (Figure 20).

a - to the light; b - in oblique light; c - in the UVL.

To simulate a solid opaque thread, overprinting with white ink in the form of a narrow strip is performed.
The appearance of such a simulation under various conditions is shown in Fig. 21.

a - to the light; b - in the UVL.

Often, imitation of a thread with text is performed in two steps. First, text (image) is applied with dark paint, and then a strip of white or translucent paint is overprinted. In this case, in reflected light, text is often visible through the paint (Fig. 22).

There are imitations of threads with text, combining an overprint of the text and a sticker on top of a strip of thin paper. In this case, the text is printed either on the surface of the document, or on a paper strip (Fig. 23). The illustration clearly shows that in oblique lighting on the reverse side, the glued strip of paper has pronounced sharp edges and increased relief.

Rice. 23. Imitation thread with a sticker paper strip:
a - to the light; b - in the UVL.

In addition, in the same figure, you can see a fairly common error made when imitating a thread with text. The fact is that on many security threads of this type, text (most often this is an alphanumeric designation of the denomination) is applied both in a direct and in a mirror and inverted image. This is done to make the text easier to read from either side. However, when imitating, this circumstance is not always paid attention to, and the text is executed only in a direct image.

It is quite common to imitate security threads by gluing strips of polymer material (film) or thin paper with texts (images) applied to them between the sides of the document. An example of such a simulation is shown in Fig. 24.

Rice. 24. Polymer strip with text,
glued between thin sheets.

Diving threads are the most difficult to imitate. In order to obtain external similarity, such threads are imitated in various ways, the most common of which are the following:

sticking off pieces of metallized foil;

stamping with printing foil (fig. 25);

finishing with paint with metal pigment “silver-like” (fig. 26).

In this case, a transparent text can be applied (for example, etched or scratched) on the metallizing foil layer in some way.
All of these methods, however, allow the effect of a diving thread to be obtained only in reflected light. When viewed through the light, such simulations look like dotted lines... To achieve greater similarity, an opaque (translucent) strip is additionally overprinted on the reverse side. In this case, however, it is rarely possible to achieve exact alignment of imitating elements on the front and back sides of the document (Fig. 27).

All of these types of imitations of security threads, as a rule, have significant differences from the genuine ones. They differ most significantly when observed in transmitted light (the degree of transparency, configuration and dimensional characteristics of texts), ultraviolet rays (the nature of luminescence or its quenching) and oblique lighting (the nature of the thickening of the paper at the location of the thread).

PROTECTIVE FIBERS

Security fibers are incorporated into the paper stock during the papermaking process. They differ from the total mass of fibers, which, in fact, constitute the paper, in some specific properties: color, the nature of luminescence under ultraviolet rays, sometimes both.

The following types of security fibers are commonly used:

colorless, luminescent in UV rays;

painted (colored), which do not glow in UVL;

colored, luminescent with their "own" color (that is, the luminescence color is close to the visible color of the fibers) or some other.

The documents may contain security fibers of one or several types at once.

In fig. 28 shows colored fibers used as security in US dollar paper.

Rice. 28. Dyed security fibers
paper banknotes of US dollars.

Such fibers are usually located in the body of the paper, but can partially (and sometimes completely) protrude onto its surface.

Colorless protective fibers are invisible under normal observation conditions - their appearance practically does not differ from the total mass. Sometimes these fibers can have a tint, most often yellowish or greenish. When illuminated with ultraviolet rays, the glow of these fibers is observed (Fig. 29).

Rice. 29. Luminescent security fibers
paper of German marks.

Imitation of protective fibers

Usually, when documents are forged, little attention is paid to the security fibers. The imitation of dyed fibers is performed by simple, affordable means, most often in the following ways:

freehand drawing;

overprint;

sticker (rare).

In cases where the fibers are imitated by drawing, their appearance depends on the tool with which they were made. For example, a colored pencil gives a “loose” picture, the thickness of the stroke changes from pressure, traces of pressure are visible (Fig. 30). In the “fibers” applied with a ball-point pen (roller), paint “discharge” is usually visible - the edges of the strokes are more intensely colored (Fig. 31).

Fiber imitation overprinted (most often offset printing) looks flat, the edges of the strokes may appear somewhat blurred (Fig. 32).

The gluing of fibers is a rather laborious process, therefore, in practice, such an imitation is rather rare.

Since fakes Low quality are often made using various copying equipment (color copiers different types), on such forgeries, the image of the fibers is usually transferred from the original along with the image of the document. In these cases, the "fibers" are inherent in the characteristics characteristic of the used copying method. For example, in Fig. 33 shows full color electrophotographic images of dyed fibers.

Rice. 33. Images of fibers,
reproduced in the process of copying.

Rice. 34. Printed fibers on three different banknotes:
the shape and location are the same.

In cases where not one, but several copies of a document are being studied - for example, a number of questionable banknotes - it is advisable to pay attention to the mutual arrangement and shape of the fibers. It is often possible to face a situation when the same arrangement and configuration of fibers is observed on different banknotes (Fig. 34). This circumstance indicates either that the fibers were imitated by overprinting (moreover, from the same printing plate), or that the same original original was used for copying.

OPTICALLY VARIABLE PAINTS

Optically variable (varying) inks are widely used today as a means of technological protection of documents. In practice, they are usually called OVI ("Oviai" - from the English Optically Variable Ink). The essence of this type of protection lies in the use of special paints of a complex composition, which, depending on the angle of illumination and observation, can change their color in a certain range.

Typically, such paints are used to apply image fragments made by intaglio printing - designations of denominations of banknotes, names of issuing institutions. Currently, OVIs are used in a wide variety of types of documents - banknotes, visas and visa coupons, securities. Almost all modern currencies are equipped with such protection.

In fig. 35 and 36 depict elements protections made with optically varying paint: the emblem of the Bank of Russia on a banknote of 500 rubles, issue of 1997, and designation of the denomination on a banknote of 100 US dollars, issue of 1996.

a - with frontal observation; b - when observed at an acute angle.

The views shown in the illustrations do not give a complete picture of the color change - only the extreme positions are shown here, but in fact the color changes smoothly as the viewing angle (or lighting) changes.

Optically variable paint imitations

The overwhelming majority of known OVI imitation methods with varying degrees of similarity reproduce only the metallic sheen effect inherent in these paints. However, such imitations do not give a change in color, which makes it easy to recognize a fake.

A variety of methods are used to obtain the glitter effect. So, in fig. 37 shows an example of imitation of OVI by applying an additional layer of a transparent substance (varnish) containing a small amount of particles of metallic pigment (powder) to the paint surface. Here we see that the contours of the varnish layer do not coincide with the border of the colored strokes.

The following illustration (fig. 38) shows an attempt at imitation by applying a metal powder to paint. In this case, you will notice that some of the powder gets onto the blank elements as well.

In fig. 39 shows a fragment of a drawing imitating OVI and made with paint, containing small shiny "flakes" of the mica type.

a - enlarged stroke fragment;
b, c - the same image at different angles.

In fig. 40a shows that the paint contains metal pigment particles. The other two figures show the same image when viewed from the front and from an acute angle: as you can see, there is no color change effect.

HOLOGRAPHIC PROTECTION

This type of protection is currently, undoubtedly, one of the most reliable due to the high adaptability of the process.

Holographic images used as security devices are made using various technologies. Without going into the details of these processes, we note that all of them are united by a large amount of transmitted information and the complexity of manufacturing.

"Classic" holograms are images made on a special metallized foil with several "plans", that is, when viewed from different angles, you can see different images, including three-dimensional ones.

A variety of holograms are the so-called kinegrams, which, when viewed from different angles, give the effect of movement or change in the geometric dimensions of the depicted object.

Examples of holographic protection of various documents are shown in Fig. 41-44.

(the effect of resizing the inscription "200" is observed).

(on the right side there are different images - a lyre and an inscription “DM”).

In addition to visible images on holograms, they are additionally equipped with microprints, which can only be seen through a microscope (Fig. 45), as well as, in some cases, hidden images, for the visualization of which special devices with laser sources and a carefully selected angle of illumination are required.

At different angles, one can see either the denomination designation or the "Britannia" figure (medallion).

- different "plans" of the image (tiger head, inscriptions, region code).

As you can see from the above illustrations, these are quite complex objects to reproduce. Therefore, as one would expect, any serious counterfeiting of holographic protection is usually not found in practice.

PAPER COMPOSITION AND ITS OPTICAL PROPERTIES

Among the characteristics of paper used as technological protection, first of all (especially for a layman) its optical properties are of interest, that is, what can be determined with the naked eye.

These properties include, for example, tinting (coloring the paper pulp, giving it a certain shade).

Shown in fig. The 46 paintings showcase the different shades of paper on Deutsche Mark banknotes. In addition, these illustrations also show one more feature that characterizes the paper of documents - the so-called marking from cloth and mesh. This indicator indicates the use of a particular paper machine - a device used to make (cast) paper.

These indicators of securities can be used, along with other characteristics, to establish the authenticity of a document.

a - in denomination of 100 marks; b - with a par value of 200 marks.
The markings from the felt and the net are visible.

Simulate paper properties

Various methods are used to simulate the paper properties of genuine documents. For example, to obtain “dull” (non-luminescent) paper in UV rays (see also the section Physical and chemical protection), various types of coatings (paints, varnishes) are applied to the paper surface in order to quench the natural luminescence of the paper.

At the same time, even papers that are similar in composition and optical properties can differ in such a parameter as the marking from felt and netting. As an example, we will give illustrations (Fig. 47), which show the difference observed in the light between the paper of original banknotes of 100 US dollars in 1996 and the paper of counterfeit class "super".

Rice. 47. Differences in marking from cloth and netting in genuine papers
and fake $ 100 bills:
a - genuine banknote (grid cells are square);
b - fake (diamond-shaped cells, diagonal).

PHYSICAL AND CHEMICAL PROTECTION

LUMINESCENT PROTECTION Simulated luminescent protection
INFRARED PROTECTION Attempts to simulate infrared protection
MAGNETIC PROTECTION Imitation of magnetic protection
OTHER KINDS OF PROTECTION

Chapter 2

When people talk about physical and chemical protection of a document, they usually mean the properties of its materials, found in various regions of the spectrum. As a rule, these are various kinds of luminescence, absorption capacity and magnetic properties of dyes. We have already considered some of the types of physical and chemical protection in the previous sections. They are often combined with other types of protection, usually technological.

The most common types of physical and chemical protection are:

• luminescence (full or fragmentary) of security threads;
• luminescence of protective fibers; “Luminescence of paints (colored or colorless);
• magnetic properties of paints and security threads;
• special dyes (so-called "tags").

In addition, there are types of protection, usually referred to simply as chemical. Most often, in this case, they mean the presence of special substances (reagents) in the composition of paper or paint, the purpose of which is to complicate or make it impossible to partially change the original content of the document (for example, by etching). At attempts of this kind of influence, the paper of the document or the used inks change their properties - usually, acquire a different color.

Physicochemical protection, in contrast to technological, is detected not visually, but with the help of special devices. These devices can be conditionally divided into two groups: visualizers and detectors (sensors). The first group allows you to visually observe the effect of protection, for example, the glow of a security element (fiber, thread, pattern) in ultraviolet rays. It can also be a picture of absorption of infrared rays or magneto-optical visualization of the properties of a dye. Devices of the second group operate on the “yes-no” principle, that is, they react to the presence of a security feature by giving a sound or light signal.

LUMINESCENT PROTECTION

This is, as a rule, the glow of security elements (fibers, threads, paints), excited by ultraviolet rays (UVL) sources in different ranges of this spectral range (see examples in Fig. 15, 29). In practice, the most common sources are 365 nm and 254 nm. Such devices can be made in the form of portable illuminators ("flashlights") or built into stationary devices.

The glow is provided due to the presence of special substances in the materials of the document, called phosphors. The range of such substances is very wide, they glow under UV light in a variety of colors, but most often - blue, yellow, green and red.

It should be noted that the so-called blankcophores, or optical brighteners, are usually introduced into the composition of "consumer" papers - writing, for printing. This is done to make the papers appear whiter. Such papers, as a rule, have a bright blue-white glow in the UVL.

In practice, the term "bank paper" is also used. It means special paper used for the manufacture of banknotes, securities and a number of other documents. Papers of this kind usually do not have pronounced luminescence in ultraviolet rays (sometimes they say "dull" in UV paper). Such properties of paper can be attributed to technological protection, since they are determined by the composition of the paper.

An example of the luminescence pattern of a banknote of 200 German marks under UV rays is shown in Fig. 48. The figure shows the glow of the security fibers of the paper, one of the paints in the background security net and paints of the serial numbers.

Rice. 48. Luminescence of a banknote of 200 German marks in ultraviolet rays

Simulated luminescent protection

Luminescent protection is used in a wide variety of types of documents. However, due to the widespread use of phosphors both in everyday life (for example, they are part of many detergents) and in production, imitation (or reproduction) of such protection is currently not particularly difficult for manufacturers of false documents.

a - genuine; b, c - fake.

An example of this is the imitation of the luminescence of background grids paints on special stamps for labeling alcoholic beverages.

In fig. 49 shows in comparison fragments of genuine and counterfeit brands, while the illustration shows differences in color and intensity of luminescence of paints and fibers.

INFRARED PROTECTION

This type of protection is based on the properties of document materials (most often, dyes) to differently absorb or transmit infrared (IR) rays.
If, for example, there is a sufficiently large number of devices available "in everyday life" to determine luminescent protection, then to detect IR protection, special devices are needed, usually used only by specialists. Therefore, such protection is usually classified as special. Although most reference publications do not indicate such signs, they are still not a secret to specialists who can use both detectors and visualizers of infrared protection equipment.

Nowadays, infrared protection is also used in such common documents as banknotes. Even the US Federal Reserve System, despite its some conservatism, began to use this type of protection in its banknotes.

Thus, all US dollar banknotes, since 1999, contain an infrared protection element in the image of the reverse side - a certain combination of transparent (invisible in infrared) vertical stripes (Fig. 50), and this combination is individual for each denomination of the banknote.

German marks contain the same kind of protection, only here the localization pattern (sometimes also called IR contrast) is somewhat more complex (Fig. 51).

Rice. 50. Absorption pattern in the infrared range
on the reverse side of the 10 US dollar banknote.

Rice. 51. And this is how the absorption picture looks like
in the infrared range on the banknote of 200 German marks.

In research practice, the term IR metamer paints has been adopted. This is the name for paints that look the same under normal conditions (under illumination and observation in the visible range of the spectrum), but differ in the nature of absorption in the infrared region.

Attempts to imitate infrared protection

It must be said that in earlier issues of US dollars, the paints also contained infrared protection elements. Thus, the inks used to print serial numbers on $ 100 banknotes and the designation of the issuing bank did not practically differ in the nature of absorption in the IR range (Fig. 52a). At the same time, even serious counterfeits, such as the "super-96" class, are easily distinguished from genuine banknotes by this characteristic (Fig. 52b).

Rice. 52. IR absorption of green dyes on banknotes
denomination of 100 US dollars:
a - genuine; b - fake "super-96".

Naturally, the reproduction (or imitation) of infrared protection is a rather difficult task for the manufacturers of counterfeit documents. However, with the appropriate instruments and reference materials, a specialist can easily distinguish a fake.

MAGNETIC PROTECTION

When it comes to magnetic protection, the presence of the magnetic properties of the materials of the document is implied. Most often these are dyes, but sometimes the magnetic properties of security threads are used as protection.

Magnetic shielding associated with dyes can be of two types. The first type assumes the presence of magnetic properties in any particular document attribute - usually this serial number... Most of the banknotes in circulation, some of the securities and other types of documents have this type of protection.

The second type of magnetic protection assumes a local distribution of magnetic properties within the image. At the same time, no external (visual) differences are observed. For example, black images on the front of US dollar banknotes are equipped with this kind of magnetic security. If you study such an image using a special device (detector or visualizer), you can find that some areas of the pattern have magnetic properties, while others do not.

Simulated magnetic protection

To simulate magnetic protection, various techniques are used, which are designed for the use of mostly simple devices (detectors). First-generation detectors were designed only to determine the presence of magnetic properties, but not their localization. Therefore, it was quite easy to "deceive" such devices - for this it was enough to produce a document using an electrophotographic apparatus ("copier") or a laser printer, in which the coloring matter has magnetic properties. Alternatively, a ferromagnet-containing substance (for example, a colorless paint with iron or nickel particles) was applied to areas of the image that were supposed to be “magnetic”. The detector then reacts to the presence of a ferromagnetic component in the dye, but cannot determine the correct location.

Methods of imitation of magnetic protection in qualified forgeries (class "super") have become more sophisticated. In this case, most likely, it is worth talking not about imitation, but about the reproduction of this type of protection. Thus, among the known counterfeits of US dollars belonging to this category, many reproduce the distribution of magnetic and non-magnetic areas quite correctly (the so-called "magnetic image" of banknotes). Nevertheless, in almost all types of "super fakes" there are some deviations from the true "magnetic image". It is difficult to judge whether this was done intentionally or not, but in practice such differences can and should be used.

An example of such a difference is shown in Fig. 53. Fragments of the “magnetic image” of genuine and counterfeit (“super” class) banknotes of 100 US dollars, issued in 1996, are shown here, recorded using a magneto-optical visualizer of the “MAG” type equipped with a video camera. It can be seen that in genuine banknotes the inscription "SERIES 1996" has no magnetic properties, and in counterfeit ones it is the other way around.

Rice. 53. Fragments of the "magnetic image" of banknotes
$ 100 denomination of 1996 issue:
a - genuine; b - fake.

OTHER KINDS OF PROTECTION

In addition to the listed species, the so-called special marks can be attributed to physical and chemical protection. This term usually means the use of dyes with special properties, the detection of which is possible only with the help of special devices (detectors or visualizers). In the reference and methodological literature, the terms "type M tags", "type I tags" are usually used. To identify these marks, various devices are used: both portable (wearable) and stationary (desktop).

There is a protection of this kind, for example, in excise and special stamps for tobacco and alcoholic products, as well as in some types of securities and other documents. Often (for example, special brands for alcoholic beverages), both security elements ("M", "I") are combined in one graphic element.

A fairly large group is formed by means of protecting documents from copying. Moreover, these funds are provided both through special printing technologies, and through the use of materials with special optical properties (dyes, polymer films, etc.).

An example of the application of this type of protection is the use of metallized paints. These paints ("silver") mark the denomination on the banknotes of Russian rubles of 1997 issue. Also, the denomination is overprinted with a special paint over the main image on banknotes of German stamps (Fig. 54).

The same illustrations show that in this section of the banknote there is also one more security element - a relief colorless image (the so-called PEAK effect).

Rice. 54. Means of protection against copying
on the banknote of 200 German marks:
a - the relief image of the inscription is clearly visible
DM 200 and the overlay appears pale gray;
b - overprint in the form of a golden strip.

POLYGRAPHIC PROTECTION

CLASSIC PRINTING: FEATURES OF BASIC PRINTING METHODS
HIGH PRINT
FLAT PRINT
DEEP PRINT
SCREEN PRINTING
SPECIAL PRINTS
MICROPRINT Attempts to simulate microprinting
BLENDED IMAGES Simulation of merged images
HIDDEN IMAGES Attempts to simulate hidden images

Chapter 3

When using these tools, two types of features are formed in documents:

• the actual signs of printing methods. They are determined mainly visually, under normal conditions or with the help of the simplest devices, for example, a magnifying glass;
• special effects indicating the use of a specific technology. Such features are usually revealed by other methods (in oblique lighting, by touch, etc.).

In order to better understand how these features are displayed in documents, it is necessary to have a general understanding of how to print. Here it is appropriate to immediately make a reservation: a detailed consideration of this issue requires a fairly deep knowledge in the field of printing. Therefore, below will be given information about the "classical" printing methods in the required volume, and then considered in more detail their varieties that have found application for the production of documents.

CLASSIC PRINTING: FEATURES OF BASIC PRINTING METHODS

Distinguish between printing methods, as a rule, according to the geometric structure of the printing plate - depending on how the printing and space (non-printing) elements on the form are separated. In this case, areas of the form that transmit ink to the print are considered to be printable, and the rest (not transmitting ink) are considered to be gaps.
Plates are often referred to collectively as clichés. It should be borne in mind that in the printing industry this term usually means illustrative forms of letterpress printing. In other literature, this concept is sometimes extended to forms for other methods.

According to this criterion, it is customary to distinguish four main printing methods:

• high;
• deep;
• flat;
• stencil.

Each of these methods has a number of varieties, some of which are usually used for printing so-called publishing products (books, newspapers, magazines), and others for the manufacture of banknotes, securities, identity documents, as well as printing on products. packages, etc.
Basically, these varieties differ from each other in the following parameters:

• method of transferring paint - direct or indirect (indirect) - is there an intermediate carrier, or a transfer link, or it is absent;
• paint viscosity - thick (viscous) or liquid (low viscosity);
• method of making a printing plate - mechanical or photomechanical (another term is photo-chemographic, that is, using photographic and chemical processes);
• purpose (type of product) - publishing, packaging, printing on products, etc.

It should be noted that images obtained by printing methods can be conditionally divided into two types:

• dashed lines, in which there are only two gradations of tone - black (color) and white;
• halftone - having intermediate tones (densities).

The methods for changing the tone can be different, they are described in the corresponding sections.

HIGH PRINT

In letterpress printing (Fig. 55), the printing elements of the printing plate are located above the blanks. Therefore, when ink is applied to such a form, it only covers the printing elements. A typical example of a letterpress form is a rubber stamp.

The ink applied to the printing elements of the form is transferred under pressure to the sensing surface (in most cases it is paper), on which an image is formed as a result - a print. In this case, a certain amount of ink is forced out of the printing elements of the form by pressure, forming a thickened layer along the edges of the strokes on the print. Rice. 56 shows a schematic illustration of a letterpress print.

Rice. 56. Schematic representation
letterpress imprint.

Extrusion of ink at the edges of the strokes is a feature inherent in all varieties of letterpress method.

In addition, as a result of the pressure of the printing plate, the receiving surface (paper) is deformed - a deepened relief is formed on the front side of the print, and a convex relief on the reverse side. This feature is typical for impressions made from solid printing plates in a direct way (without an intermediate carrier or, otherwise, a transfer surface). This technology is usually referred to when talking about "classic" letterpress; it is sometimes also called typographic printing.

The characteristic features of a letterpress impression are shown in Fig. 57.

a - extrusion of paint on the edges of the strokes from the front side;
b - convex relief from the reverse side.

The letterpress printing method also includes: flexographic printing (flexography) and typo-offset (high offset). These technologies are usually referred to as special printing methods.

Flexography is a type of direct letterpress printing that uses flexible printing plates and low-viscosity inks. This method is mainly used for printing on packaging.

Typofset is an indirect method, where the printing plate is a form of letterpress, but the ink is transferred from it first to the intermediate surface (offset cylinder), and then to the substrate (paper or other material). Typooffset, more precisely, its special modifications, is used in the production of documents (see. Special printing methods).

In the production of documents, letterpress printing is mainly used to apply variable details, for example, serial numbers.

In cases where the number is applied directly to the substrate (paper), the impression is characterized by the features of the "classic" letterpress printing - ink squeezing out on the edges of the strokes from the front side (Fig. 58) and a raised relief on the back side.

If the number is applied over another image, for example, a background grid or a main pattern, the nature of the lying paint can be different. Thus, the numbers printed over the background grids, executed by methods of offset or letterpress (Orlov) printing, are characterized by practically the same features as the "classic" letterpress printing (Fig. 59).

Rice. 59.	Rice. 60.

And if the image is made, for example, by metallography, then the morphology of the number strokes changes significantly. In fig. 60 shows the case when the serial number is applied to the main drawing of the banknote (Estonian kroons), made by intaglio printing method. Since the intaglio print has its own convex relief, the paint in the strokes of the number lays down unevenly, in accordance with these irregularities.

This combination of printing methods - high in intagliography - is also found in the familiar US dollar banknotes. On them the seal of the Treasury (green, on the right side) is carried out by letterpress printing, over the designation of the denomination of the banknote, which is printed intaglio. The relief of the main image is large enough to prevent the green ink from penetrating the paper. Therefore, in most cases on genuine dollars for the image of the seal of the Treasury, incomplete imprinting of areas superimposed on the image of numbers or letters denoting the denomination is characteristic (Fig. 61).

Rice. 61.

FLAT PRINT

A characteristic feature of flatbed printing is the absence of spatial separation of printing and space elements of the printing plate.

In the forms of flat printing, printing and space elements differ not in height, but in their physicochemical properties. In the process of making forms, special processing is carried out, as a result of which the printing elements acquire the ability to perceive the ink, and the blank ones - to repel it.

In the printing literature, when describing the flat printing process, the terms oleophilicity (hydrophobicity) and oleophobicity (hydrophilicity) are usually used. The first two terms mean the ability of the printing elements to perceive ink and repel water, the other two - the ability of whitespace elements to repel ink and perceive water. To obtain these properties in flatbed printing, the surface of the printing plate must be moistened before ink is applied.

Depending on the material of the printing plate, its physical and chemical preparation, as well as the method of image transfer, in flat printing it is customary to distinguish between offset, lithographic and phototype printing.

Usually, when it comes to flat printing, first of all, they mean offset printing.

Actually, the full name of this technology is flat offset printing. Here the term "flat" refers to the geometry of the printing plate, and "offset" denotes a method of transferring paint from a form to a receiving surface and implies the presence of an intermediate (transfer) link. Usually it is a cylinder covered with rubber. It is called offset (from English to set off) - it takes paint from the form and transfers it to paper. In everyday life, the name "flat" is often omitted, calling this method simply offset printing (offset).

Thus, offset printing is an indirect method of flat printing, the diagram of which is shown in Fig. 62.

Due to the uniform distribution of pressure over the surface of the form, offset prints are distinguished by uniform coloration of the printing elements and clear contours, as well as the absence of paper deformation from the pressure of the form.

These features are demonstrated by the diagram shown in Fig. 63.

Currently, offset printing is the most widespread method of printing reproduction.

It is used both for printing publishing products (books, newspapers, magazines) and for producing a wide variety of types of documents.

In fig. 64 shows a fragment of a print of the "classic" offset printing - this is the text in the book.

Rice. 64.

Lithographic printing (lithography) is historically the earliest method of flat printing. It was developed at the end of the 18th century. Special stones were used here as printing plates, the surface of which, after chemical treatment, acquired oleophilic and oleophobic properties. This is a direct printing method.

Currently, lithography is used only for printing special (most often copyright) art publications.

The methods of flat printing include phototype printing (phototype). This is a direct printing method in which the photosensitive layer is based on gelatin.

Phototype is the only one of the "classic" types of printing that allows you to transfer halftones without the help of a raster. The technology for making phototype printing plates is rather complicated, and the printing process is unstable.

According to some estimates, this method is considered to be almost ideal for reproducing grayscale images. However, phototype printing is currently used extremely rarely (reproductions of paintings, facsimile prints) precisely because of the instability of the printing process.

In documents - securities, banknotes and other types - offset printing is used mainly for printing background images: protective nets, patterns, and also, in some cases, for applying text and graphic details.

In fig. 65 shows a fragment of the background image on a banknote (Kyrgyz som).

Rice. 65.

DEEP PRINT

In the method of intaglio printing (Fig. 66), printing plates are used, on which the printing elements are lower than the blank ones. The paint applied to this form covers its entire surface. Therefore, before starting the transfer (printing), the ink from the blank elements is cleaned off with the help of some device - a flat knife (squeegee) or a roller.

It should be noted that gravure printing is practically the only way where it is possible to obtain an ink layer of various thicknesses. The figure shows that the printing elements of the form have different depths.

Speaking about intaglio printing, it should be borne in mind that its most common varieties have fundamental differences.

Blade gravure printing (commonly referred to simply as gravure printing) is a "classic" printing method and is commonly used for the production of printed products in large circulation (magazines, advertising products, packaging). It is generally accepted that this method provides the best print quality for halftone images.

In this method, low viscosity ink is transferred directly from the cells of the printing plate to the substrate (direct method). It should be noted that the technology of manufacturing a printing plate in this case implies the use of a raster, that is, the entire surface of the form, whether it be text or an illustration, is divided into raster elements (dots of the same size). This is reflected in the print, the diagram of which is shown in Fig. 67.

Rice. 67. Schematic representation
gravure print.

The appearance of the impression made by the squeegee gravure printing method is shown in Fig. 68. The illustration shows that thin strokes of the print are broken up practically into separate points, and in wide strokes the raster structure is better visible at the edges in the form of "teeth" (sometimes they speak of a "sawtooth" structure).

In addition to squeegee, intaglio printing (intaglio printing) and tampon printing (tampon printing) are referred to the intaglio printing method.

In intaglio printing, high-viscosity printing ink is transferred from an engraved or etched plate directly to the substrate (direct method).

a - subdivision of thin strokes, b - "teeth" at the edges of wide strokes.

Most often, metallographic prints are line images (engravings).

Metallography is most often used for the production of banknotes, securities, identity documents (see. Special printing methods).

Pad printing is an indirect method of intaglio printing. With this technology, an elastic swab (intermediate carrier) transfers ink from a metal (engraved or etched) or photopolymer printing plate to the receiving surface.

Tampon printing is mainly used for printing on various packaging materials or on products with unusual geometry (for example, bottle caps, button buttons, souvenirs, etc.).

SCREEN PRINTING

The name of this method speaks for itself - the printing plate here is a stencil. True, unlike the usual stencil in the form of a sheet of paper, cardboard, film with letters or a pattern cut through them, the form of "classic" screen printing is a mesh stretched over a frame. On this grid, in one way or another, printing and space elements are formed - the printing ones let the ink pass to the paper, but the space ones do not.

Thus, ink in screen printing enters the substrate by forcing through the mesh (Fig. 69).

This method of ink application determines the type of screen-printed impressions - they always display the grid structure in one way or another (Fig. 70).

This method also has several varieties, however, of which only silk-screening finds industrial application.

Rice. 70. Schematic representation
screen print.

The term silk-screening reflects the history of this method - in the old days, nets were made from silk fabrics. In the literature, you can also find the names etmography and serigraphy - they all mean the same printing method. Most often, it is called simply screen printing.

Unlike other "classical" methods, in screen printing it is possible to obtain a very thick layer of ink (up to 100 microns), which determines the scope of its application.

The thickness of the ink layer largely depends on the thickness of the filaments, and the resolution of the process depends on the density of the mesh. In fig. 71 shows a view of screen-printed impressions from molds made on meshes of different densities.

Even in cases where there are no breaks in the strokes in the screen-printed print, oblique light, as a rule, still displays the grid structure in the form of a characteristic systematic relief on the surface of the ink layer (Fig. 72).

Screen printing is a very old method, however, nowadays it is mainly used for printing small quantities in those areas where a large thickness of the ink layer or saturation is required (product marking, posters, wallpaper production, as well as the sphere of artistic graphics).

Rice. 71. Fragments of screen-printing impressions:
a - with a coarse mesh (with large cells);
b - with a fine mesh (with small cells).

In addition, the screen printing method also includes rotator printing, a modern variety of which is risography. These technologies can be attributed to office methods of reproduction of documentation or, as they said earlier, to operational printing.

Rice. 71.

Screen printing is practically not used for printing original documents, however, this method is often used (given the possibility of obtaining a thick ink layer) when imitating a relief characteristic, for example, for intagliography.

SPECIAL PRINTS

As the name implies, it is customary to refer to this group of printing technologies types of printing that have a special area of ​​application.

In this case, this group may include certain methods, depending on the basis of the classification: the materials used, the type and purpose of the product, the possibility of obtaining unusual effects, etc. However, all special types of printing have one property in common - these technologies are not used for printing standard or publishing products (books, magazines, newspapers, etc.). Although special types are variants of their "older brothers" - classic technologies, it is this characteristic that distinguishes them into a special group.

In this case, we will only talk about those special types of printing that are used in the manufacture of documents - in the context of the subject under discussion. Therefore, the following technologies will be of interest to us:

Oryol seal;

typooffset;

metallography (including multicolor);

iris print.

The first two types of printing are indirect methods of letterpress printing.

Oryol printing is a method of obtaining multicolor images from a single printing plate.

It is necessary to clarify here that in classical printing (regardless of the printing method), the principle of synthesizing a multicolor image is used. In accordance with this principle, all the required colors can be obtained using a limited number of inks - in most cases four, the so-called basic - cyan, magenta, yellow and black. Intermediate colors in this case are formed due to various combinations of the main ones. In this case, at least four printing plates (usually called color separations) are required to obtain a multicolor impression. In this case, the application of paints to the substrate (paper) occurs sequentially, that is, each printing plate applies paint of the same color.

In Oryol printing, all the paints are first applied to one printing plate, and then they are all transferred to paper at the same time.

Technically, this is a very complex process, such printing is possible only with the presence of special - unique and hard-to-find equipment. Since our task is not to study the technical subtleties of this process, it is only important to note the features that characterize it, which are found in the study of documents.

As long as the printing plate is one, in the prints of the Oryol seal, displacements of areas with different colors relative to each other are never observed. At the same time, in the places of transition from one color to another, with magnification, you can see that the paints seem to mix, forming a small area of ​​"transitional" color. In addition, being still a kind of letterpress printing, the Oryol seal carries the features inherent in this method, namely, traces of ink squeezing out on the edges of the printing elements.

All these features are clearly visible in Fig. 73.

It must be said that in the modern production of documents, other technologies are also used that allow obtaining a multicolor image from a single printing plate. However, in them prints are applied not from letterpress forms, but from others - for example, gravure. In such cases, it is sometimes said about the "effect of the Orlov seal." Some of these technologies will be discussed below.

Rice. 73. This is how the print looks when enlarged,
made by the method of Oryol seal
(background grid on the pages of the passport of a citizen of the USSR).

Typooffset, as the name implies, combines two technologies: the printing plate is a form of high (typographic) printing, and the image is transferred to paper through an intermediate medium - the offset principle.

This combination also determines the features revealed in the documents produced by this method. On the one hand, the use of letterpress forms causes ink to be squeezed out at the edges of the printing elements. On the other hand, the presence of an intermediate carrier - an offset cylinder - means that there is no deformation of the paper from the pressure (onslaught) of the printing plate.

In fig. 74 illustrates the specified features of the print made by the type offset method.

(a fragment of the image on the banknotes of Russian rubles).

Sometimes in the literature, typeoffset is called high offset, meaning the form of letterpress printing. There is also the name dry offset, that is, it does not require wetting, in contrast to flat offset printing. The latter term, however, is not entirely correct, as it usually refers to another technology.

Metallography is a type of direct gravure printing, which is recognized and one of the most powerful means of printing documents security.

A printing plate in metallography is usually a line engraving made on metal (most often copper or steel).

This technique is also called incisor engraving. However, the industry usually does not use original engravings (hand-made by an engraver), but their electroformed copies. The use of electroforming makes it possible to obtain practically identical copies of the original engravings, which makes it possible to use metallography for printing large quantities of documents - banknotes, securities and other similar products.

In this case, the nature of the transmission of halftones in the image is fundamentally different from that used in the "classic" squeegee gravure printing. In metallography, images are usually line, not raster. Halftones are transmitted here, firstly, by changing the width of the strokes, and secondly, due to the different depths of the elements of the printing plate and, accordingly, the thickness of the ink layer on the print.

In addition, in intaglio printing, a very high pressure is required to transfer viscous ink from the deep printing elements of the form to the paper normally.

For these reasons, in the impressions obtained by the metallographic method, strokes are formed, which are distinguished by a significant relief. On the one hand, the relief is caused by high pressure (the surface of the stroke becomes convex even without paint), and on the other hand, a rather thick layer of viscous paint is applied to this convex surface.

Rice. 75. Metallographic impressions:
a - convex relief on the front side;
b - concave on the reverse.

In addition, a concave relief is formed on the reverse side of the print by pressing the paper into the recessed elements of the printing plate. Rice. 75 just shows these features of intaglio prints.

There are a number of other features inherent in metallography. To retain ink in the printing elements of the form, which have a large area, they are broken into smaller areas. In this case, impressions usually display a structure in the form of grids of various densities - "frequent" or "rare". Such are, for example, the structures of strokes in large inscriptions on US dollars (Fig. 76a) or in the drawing of tickets for travel in Moscow city transport (Fig. 76b).

a - in inscriptions on US dollars;
b - in the figure of travel passes.

Multicolor metallography is also used for the production of documents. In this case, like the Oryol seal, all inks are applied to the print from a single printing plate. Therefore, in the prints one can observe, firstly, the features characteristic of metallography (relief from the face and back), and secondly, the "Orlov seal effect", that is, the absence of displacements and breaks at the boundaries of areas of different colors. Only in the case of multicolor metallography, the zones where the paints are mixed can be either very narrow (Fig. 77a) or rather wide (Fig. 77b).

a - a sharp transition (inscriptions on German stamps);
b - smooth (special brands "Strong alcoholic drinks").

Iris printing, in fact, is not a printing method, but is a special technology for applying several colors to one printing plate (regardless of its type - high or flat). In this case, all inks are also applied to the paper at the same time, however, their distribution over the surface of the form is carried out by the inking apparatus of the printing machine. As a result, the paints are mixed with each other, forming blurry multi-colored stripes. In this case, on the prints, you can observe a smooth change in the color of the strokes (iris roll). Single transitions are possible (fig. 78a); there may be reverse transitions, sometimes called counter roll (Fig. 78b).

a - single transition (background grid on special stamps);
b - double transition, or counter roll (background grid in Russian rubles).

OTHER WAYS OF POLYGRAPHIC PROTECTION

In addition to the features caused by the printing method itself, the features of the so-called graphic protection, which are formed when using special technological methods and complex graphic elements, also belong to the printing protection. Some of these are discussed in the following sections.

MICROPRINT

As one of the most common means of graphic protection in documents, microtexts are used - texts in which the size of characters is less than 0.4 mm (usually 0.2-0.4 mm). This element is carried out mainly by intagliography and offset printing (or typo-offset).

The content of the microtext usually includes the name of the country, document and (or) issuer, denomination (in letters or numbers) and some other designations.
The range of microtexts is very extensive. Most often, there are positive microtexts, that is, made with dark signs on a light background. Example - US dollars, where microtexts of this type are used in various forms: lines of text in an oval frame (Fig. 79a), inside the denomination figures (Fig. 796, c, d), as well as in guilloche frames (Fig. 79e). All these microtexts are made by intaglio printing.

Rice. 79 a, b, c, d, e. Positive microtexts in US dollars of various denominations.

Positive microtexts are also used to protect passport blanks, for example, in the form of designating "corners" for photographs (Fig. 80), and in excise stamps - in a circle around the coat of arms (Fig. 81). In the examples given, the microtexts are offset printing.

Rice. 80. Positive microtext
on the foreign passport of the USSR.

Rice. 81. Positive microtext
on the excise stamp
"Tobacco products (RUSSIA)".

Rice. 82. Microtext in negative image
on the banknote of 500 rubles of Russia.

In addition to positive ones, there are also microtexts made in a negative image (with light characters on a dark background). They are sometimes also called inverted. An example of negative microtext is shown in Fig. 82.

All the microtexts shown above can be considered regular - all characters in them have the same height and width of strokes. However, other types are quite widely used - for example, with variable stroke thickness (Fig. 83) or the height of characters (Fig. 84). Such microtexts are used as elements of document design and form various visual effects. On Ukrainian hryvnia banknotes, for example, the bends of the microtext lines form a pattern of larger numbers - in Fig. 85 is the number "2".

Rice. 83. Variable thickness of microtext strokes
on the banknote with a denomination of 100 German marks.

Rice. 84. Variable height of characters
microtext (excise stamps).

Rice. 85. Microtext that forms the picture
the numbers "2" on the 2 hryvnia banknote.

Rice. 86. Transition from negative microtext
to the positive value on the banknote
1000 rubles of Russia.

Combinations of styles such as a smooth transition from negative to positive are also used (Fig. 86). Sometimes microtext is not located in any specific place (not locally), but is "scattered" over a large area on the background of the document, as on Danish krone banknotes (Fig. 87).

Attempts to simulate microprinting

Microtexts are displayed with varying degrees of accuracy in document forgery. In most cases, when it comes to copying technologies (reprography) or simple printing processes, microtexts are reproduced with significant distortions.

A fragment of a counterfeit banknote made by the offset printing method is shown in Fig. 88. Here, all the main black images on the front side were reproduced using a raster, and the microtext inside the numbers “100” was retouched (traced) at the stage of making a photographic form.

Another example illustrates a fake, when the microtext is readable enough, but in this case we see that the signs of the text are still distorted (Fig. 89).

Rice. 88. Barred microtext on fake
banknote made with raster shape.

Rarely, but such falsifications are also encountered in practice, where the microtext does not correspond at all in content to the original.Example in fig. 90 illustrates a forgery of an excise stamp similar to that shown in Fig. 81.

Rice. 90.

COMBINED IMAGES

Combined images are considered to be another type of polygraphic security. There are two types of such images in documents.

The former is most common in one page documents, especially banknotes. This type of composite image is commonly referred to as continuous. Why they are called that way can be seen from the illustration (Fig. 91). Due to the use of a special technology, the images at the edges of the banknotes are so precisely aligned that they seem to be a continuation of each other - both in graphics and in color. Such a picture can be observed if you fold a banknote into a ring or combine the upper and lower edges of two identical banknotes.

(10 rubles in 1997).

Aligned images of a different type - they are also called alignment marks or enlightened registers - are observed when viewing a document in light. This type of protection is also based on the use of special technologies, thanks to which an almost perfect alignment of the images of the front and back sides is achieved.

Usually such images are a certain set of graphic elements, some of which are located on one side of the document, and part on the opposite side. A typical example of such protection is overlaid images on German stamps. They contain fragments of the letter D placed in a hexagon (Fig. 92). When viewed through the light, these fragments complement each other, and a single image is formed.

a - a fragment on the front side; b - on the reverse; c - view to the skylight.

Simulating merged images

Since in the overwhelming majority of cases, simplified technological schemes are used for forging documents, it is quite rare to achieve good alignment of the images of the front and back sides. The discrepancy is often on the order of 1–2 mm.

Rice. 93. Composite image on fake
banknote of 1000 German marks (view through the skylight).

In some cases, however, fairly good results are obtained, for example, as shown in Fig. 93. However, such an effect is more likely possible with single counterfeits or very small editions. Massive forgeries are unlikely to withstand any criticism.

HIDDEN IMAGES

This protection category includes images made using special techniques that make it difficult to reproduce or imitate the original (genuine document). Predominantly latent images - sometimes called graphic traps - are designed to protect a document from copying, that is, reprographic reproduction.

"Traps" are usually fragments of images with a regular structure - it can be a "classic" (dotted) or linear raster (groups of lines of the same or different widths and directions). The combination of such elements forms a kind of "hidden" pattern at the microscopic level. Outwardly (under normal viewing) such areas look like evenly colored areas of the background, and when magnified, their true structure is visible.

Examples of this kind of "traps" are shown in Fig. 94 and 95. In the first case, a fragment of a banknote (these are stamps of Germany) is shown, where groups of parallel lines directed at different angles are applied.

In the second, it is a fragment of a railway ticket on which the word "FALSE" is made using dot patterns of different frequencies (lineatures).

Attempts to simulate hidden images

When trying to reproduce (copy) a document containing a latent image, or "trap", it is almost inevitable that a certain visual effect will form in certain parts of the copy - either a moire pattern appears, or some word or pattern "appears".

For example, in Fig. 96 shows a moiré pattern formed on an area of ​​a counterfeit banknote reproduced from a raster printing plate. This is the same area, the original view of which is shown in Fig. 94.

In fig. 97 shows how the inscription “FALSE” appears when attempting to counterfeit (copy) a railway ticket (compare with Fig. 95).

Imitation of methods of polygraphic protection

Practically all known "classical" technologies are used to simulate the effects obtained when using special techniques and printing methods. However, in this case it is possible to reproduce, as a rule, only part of the features inherent in genuine prints. Some imitations successfully convey the general appearance and color of the image, others - tangible features (relief), and others allow you to reproduce small details. Therefore, a whole set of technologies is often used, which forms a semblance of features obtained in an original document using one special printing method.

Examples of this combination of technologies are document forgeries that attempt to imitate intaglio printing.

On the one hand, in this case, they try to convey the features of the structure, or morphology, of strokes, and on the other, to imitate the relief characteristic of metallographic prints. Attempts to simulate relief are usually more successful.

The most common method in practice is imitation of relief by embossing. At the same time, various rigid printing forms (cliches) are used, both with convex and concave printing elements.

a - in US dollars; b - in Russian rubles; c - on travel passes.

Accordingly, the embossing is performed either on the front or on the back side of the document sheet, over the already applied visible image. The visible image itself can be executed in almost any way of printing.

In fig. 98 shows examples of such relief simulations. If we compare the observed picture with similar fragments of genuine documents (see Special Printing Methods), it is possible to quite unambiguously distinguish fakes, first of all, by the discrepancy between the painted image and the embossed (embossed) image.

In practice, there are other methods of creating a relief image, for example, the so-called thermography. This method is quite widespread for printing business cards, brochures and other promotional products. Its essence lies in the fact that polymer powder is sprayed onto the "raw" paint, which is then melted. In this case, a transparent glassy layer with a rather pronounced relief is formed on the surface of the striae (Fig. 99a). This method is also used to simulate the relief of intaglio prints.

Relatively recently, the so-called phase, or solid ink, printers have become widespread. This is one of the varieties of inkjet technology printing, which does not use liquid ink, but solid (fusible). Without going into the details of the technology, we note that in this case, the strokes of the image are also obtained in relief (Fig. 99 b).

Of course, for a specialist, the definition of such fakes is not particularly difficult, but nevertheless, the relief obtained by these methods is quite capable of misleading an ordinary consumer.

It is much more difficult to imitate the features of the structure (morphology) of the strokes. "Classical" printing technologies are not able to convey the true picture, for example, intaglio printing. In fig. 100 shows the same area of ​​counterfeit banknotes produced different ways(these are US dollars issued before 1996). It is easy to see that the pattern of the stroke structure is, firstly, different, and secondly, it differs from the stroke morphology of genuine banknotes - for comparison, you can refer to Fig. 76a.

a - thermography; b - phase (solid ink) printer.

a - offset; b - stencil; c - intaglio printing from etched forms;
d - intaglio printing from engraved forms (shallow relief).

Some similarities with the “mesh” engraving characteristic of intaglio printing (Fig. 101a) have prints obtained by the method of screen printing - they have both a relief and a similar structure (Fig. 101b).

a - metallography method;
b - screen printing (silk-screen printing).

When counterfeiting, they often try to reproduce the high color intensity of intaglio strokes. For this, in particular, an additional second layer of darker paint is applied. In these cases, often the first and second images do not match exactly, as can be seen in Fig. 102.

All of the above does not apply, of course, to highly qualified fakes of the "super" type. Since in this case the same technology is used - intaglio printing - differences in morphology are very insignificant or completely absent. To identify such forgeries, a scrupulous comparison of the smallest features of the original and the controversial document is necessary. In most cases, this bears fruit - in Fig. 103 shows fragments of a genuine banknote and a "super-forgery" version of the 1996 model. The above illustrations clearly show the difference: on a genuine banknote, shaded with the letter N, there is a solid black area, on a counterfeit one, an oblique white stroke.

Rice. 103. Graphic differences between genuine
banknote (a) and "super forgery" (b).

Particularly difficult to reproduce are the elements of the picture, made by special methods of multicolor printing.

In these cases, using conventional color reproduction technologies, counterfeiters are forced to use several printing plates (according to the number of colors). With this approach, it is necessary to combine images of different colors, which is not always possible, especially with a large circulation. Examples of such attempts are shown in Fig. 104. Fragments of fake special stamps for labeling alcoholic beverages are shown here. Note that in this case, various methods of color matching were used: "overlap" (Fig. 104a, b) and "end-to-end" (Fig. 104c, d).

Compare this effect with fig. 77b.

a, b - more "successful"; b, d - worse (mismatch is visible).

The same is the case with the imitation of iris roll. For the correct or at least close transmission of this effect, you have to either change the width of the strokes (Fig. 105a), or break them into points or segments (Fig. 1056). None of this is seen in authentic documents - refer to fig. 78a.

a - a change in the thickness of the strokes; b - raster splitting.

A FEW USEFUL TIPS

Dear Reader!

This book introduced you to the main ways of protecting documents and methods of detecting forgeries. We hope that the information received will be useful - both if you have already dealt with the study of documents, and if everything written was somehow known to you earlier.

Of course, one should not think that the material presented covers all possible options that you may encounter in practice. The developers of protection means will definitely come up with something new, and, accordingly, there will be "skillful hands" who will find opportunities to imitate such technologies.

Therefore, it is impossible even to imagine all possible ways to imitate security features of documents. The human mind is so inventive that one cannot even try to cover the whole range of possible ways of forging documents. Yes, this is not necessary, if you follow a few simple rules.

Second (stems from the first): if there is no sample, you must have at least an official (or professional) description. Then you can compare the data obtained as a result of research with this description.

At the same time, strictly follow the well-known postulate: look not for similarities, but for differences!

Third: for a correct conclusion, one coinciding or differing feature is not enough. Remember that protection is a complex of attributes. If something distinguishes the document under examination from the sample, try to determine if this is the result of technological deviations in the process of making the original document.

Fourth: there are still cases when it is possible to draw a conclusion about a fake without a sample. For example: the images on the banknote under investigation were made by the method of inkjet printing.

This means that it is definitely fake - genuine banknotes are not printed on inkjet printers! Or: The watermark image is overprinted. So this is not a natural watermark, but an imitation. And so on - turn on the logic.

Fifth: human senses are not able to correctly assess the entire set of protective features. Even a very experienced technician cannot see ultraviolet luminescence, much less an absorption pattern in the infrared region. This requires special tools, namely devices.

In the relevant sections of the book, there are directions on the recommended research methods. Some of them can be implemented without instruments, but nevertheless, any person should have at least a minimum of instrumental controls. Depending on your qualifications and experience, a different number of such funds will be required - you yourself decide how much and what.

We would like to bring to your attention a range of devices manufactured by VILDIS, which has been developing authenticity control devices for many years. The table below shows the devices manufactured by this company - from the simplest detectors (they "beep" or "blink", indicating the presence or absence of a security feature) to professional expert devices that allow not only to see, but also to fix security features.

	White reflected ny light	White pass- giving light	White oblique fall. light	Magnifier	Uv 365 nm	UV.		.
ULTRAMAG - 122 ML				.	.				.	.
ULTRAMAG - 122 M					.				.	.
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