Anti-counterfeiting printed materials

Abstract

The present invention provides a latent image print in which a printed image is formed by combining a first image formed with a luminous colorant and a second image formed with a colored colorant of the same hue, and in which the image visible changes depending on the viewing angle, and the image change effect is clear. [Solution] The invention comprises a first image formed from a luminous colorant and a second image formed from a colored colorant of the same hue as the luminous colorant, wherein the first image is divided into an information section representing first significant information and a background section surrounding it, and the second image is formed by regularly arranged latent image elements representing second significant information, the background section and latent image elements are formed with visually equivalent colors, and the first image and the second image are fitted together.

Description

Technical Field

[0001] The present invention relates to an anti-counterfeiting printed matter that changes into different images according to the angle of incident light of an observable image in the field of security printed matters such as banknotes, passports, securities, identity certificates, cards, tickets, etc. that require an anti-counterfeiting effect.

Background Art

[0002] Due to the recent progress of digital devices such as scanners, printers, color copiers, etc., it has become possible to easily produce sophisticated replicas of valuable printed matters. As one of the anti-counterfeiting technologies to prevent such replication and forgery, there are many that have an optical security element such as a hologram where the image changes depending on the printed matter or the viewing angle.

[0003] However, different from the conventional anti-counterfeiting technology formed by printing using ink, a hologram is formed using a complicated manufacturing process and special materials. Therefore, it takes more time and effort in manufacturing compared to conventional anti-counterfeiting printed matters and is extremely expensive. For this reason, special light-reflective powders such as metal ink, interference mica, oxidized flake mica, pigment-coated aluminum flakes, and optically variable flakes are blended into ink or paint, and by using the superposition of special materials and a complicated halftone pattern, an anti-counterfeiting printed matter that can be formed by a general printing method and realizes the same image change as a hologram has emerged (see, for example, Patent Document 1 and Patent Document 2).

[0004] In addition, recent advancements in DTP technology have led to the availability of high-performance printers capable of expressing metallic textures using metallic toners such as gold and silver. Using these printers, it has become possible to easily produce the aforementioned anti-counterfeiting printed materials without using dedicated printing presses such as offset or gravure printers. In this case, the applicant has already filed patent applications for anti-counterfeiting printed materials that can be printed using a printing press or output by a printer, using a combination of silver and black (see, for example, Patent Documents 3 and 4). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 3398758 [Patent Document 2] Patent No. 4604209 [Patent Document 3] Patent No. 6504564 [Patent Document 4] Japanese Patent Publication No. 2022-111419 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0006] Regarding the technology described in Patent Document 1, there was a problem in that, because the luminous material constituting the first printed image and the color material constituting the second printed image have different hues, the second printed image, which should not be visible, becomes visible when observed under diffuse reflected light. Furthermore, because the second printed image is composed of a sparse area ratio, there was a problem in that the visibility of the second printed image that appears under specular reflected light is low.

[0007] The technology described in Patent Document 2 is a technique for forming anti-counterfeiting printed materials by layering a glossy material and transparent ink. Unlike the technology in Patent Document 1, which uses color materials for latent image formation, the ink used to form the latent image is transparent, eliminating the need for color adjustment, and the latent image is not visible under diffuse reflected light. Therefore, this technology offers excellent image switchability. However, because it uses transparent ink that is invisible to the naked eye, there is a problem in that it is difficult to control the print quality during manufacturing. Furthermore, when considering output by printer, printers that can print transparent color materials are currently rare, making it unsuitable for printer output.

[0008] Furthermore, the technologies described in Patent Documents 3 and 4 are characterized by the fact that, by using a printer that can use metallic toner such as silver in combination with a black colorant, it is possible to output printed materials without using an offset printing press. When outputting with a printer using this technology, there is no need to create a printing plate, so it becomes possible to print variable information, where the content of each output is all different information, and in particular, it is possible to personalize the meaningful information represented by the anti-counterfeiting technology to include personal information such as names and ID numbers.

[0009] However, the technology described in Patent Document 3 requires fine-tuning of the density to maintain the same color between silver and black for each gradation of the visible image as seen under diffuse reflected light. This presents a problem in that it is time-consuming to create and adjust when the visible image is a multi-gradation image with multiple gradations.

[0010] Furthermore, although the technology described in Patent Document 4 is easy to manufacture, it incorporates the gradation of the visible image present in a certain region into the latent image. As a result, the gradation of the visible image is reflected in the latent image that appears during specular reflection, leading to the problem of an unclear latent image.

[0011] The present invention aims to solve the aforementioned problems and provides a printed material that has the effect of changing the image under diffuse and specular reflected light, formed by pairing a colorant containing a glossy material with a colored material of the same hue as the glossy material, and is easy to manufacture, has a high image change effect, and is a cost-effective anti-counterfeiting printed material that can be adapted to variable printing by printer output. [Means for solving the problem]

[0012] The present invention provides a printed image having a different color from the substrate on at least a portion of the substrate, wherein the printed image is formed from a colorant having lustrous properties and comprises a first image having first significant information, and a second image having second significant information, which is formed from a colored material having the same hue as the colorant having lustrous properties under diffuse reflected light, wherein the first image consists of an information section and a background section, the information section consists of a plurality of information elements arranged regularly, the background section consists of a plurality of background elements and white-out elements arranged regularly, the second image consists of a plurality of latent image elements arranged regularly, with white-out elements and latent image elements fitted together, and the background elements and latent image elements are formed with visually equivalent colors, wherein under diffuse reflected light, the first significant information can be seen by the difference between the area ratio per unit area of ​​the background section and the area ratio per unit area of ​​the information section and latent image section, and under specular reflected light, the second significant information can be seen by the difference in the reflective properties of the colorants.

[0013] The characteristic feature is that the colorant having lustrous properties is a silver colorant, and the colored colorant is a black colorant.

[0014] The material has a third image formed by a colorant that is the same color as the substrate or a transparent colorant, and the third image has a light / dark flip-flop property and is superimposed on all non-image areas of the printed image. [Effects of the Invention]

[0015] Unlike the technology described in Patent Document 1, the anti-counterfeiting printed material of the present invention has a second image that appears under specular reflection, which is completely camouflaged by being superimposed on the first image. Therefore, it is invisible under diffuse reflection and has high latent image concealment capabilities.

[0016] Furthermore, since the anti-counterfeiting printed materials of the present invention do not use transparent ink like the conventional technology described in Patent Document 2, there is no need to manage latent images by making them emit light as in the conventional technology. Quality control is easy as the quality of the image formed by colored ink can be managed visually. Consequently, once the two images are superimposed to form a finished printed image, it is difficult to discern its composition, resulting in high resistance to counterfeiting.

[0017] The color matching of the two color materials constituting the anti-counterfeiting printed material of the present invention only requires adjusting the background element and the latent image element to the same color. Unlike the prior art described in Patent Document 3, there is no need to fine-tune the density for each gradation of the information section, making production easy.

[0018] Furthermore, the anti-counterfeiting printed material of the present invention does not require the incorporation of the grayscale of the first significant information of the first image into the latent image; the grayscale of the latent image is used solely to represent the second significant information. Therefore, unlike the technology of Patent Document 4, the problem of the grayscale of the visible image being reflected in the latent image that appears during specular reflection, resulting in an unclear latent image, does not occur. In addition to the high concealment of the latent image under diffuse reflection as described above, the clarity of the latent image that appears during specular reflection means that the switch between the visible image and the latent image occurs clearly in an instant, resulting in an extremely high change effect.

[0019] Furthermore, when forming the anti-counterfeiting printed matter of the present invention by printing, the two images constituting the anti-counterfeiting printed matter can be formed with one being a pigment having brightness and the other being a pigment having the same hue as the pigment having brightness. When the pigment having brightness is silver, the paired pigment is black, and this black is a pigment basically used for all printed matters. Therefore, it can be made common with the pigments constituting other design elements of the printed matter on which this anti-counterfeiting printed matter is formed, and it is not necessary to specifically use two pairs of pigments to form this technology. All that needs to be prepared only for forming the anti-counterfeiting technology is only 1 color of the pigment having brightness. Thus, this technology can be configured by using 1 cylinder in the printing unit, and different colored inks can be put into other printing cylinders to form design elements other than the anti-counterfeiting technology. As a result, the degree of freedom in color design of design elements other than the anti-counterfeiting technology in the printed matter can be increased. Also, even when outputting the anti-counterfeiting printed matter with a printer, since the black pigment is a pigment that is always set in the printer, the anti-counterfeiting printed matter of the present invention can be produced by preparing only the silver pigment. In this case, different from the case of using a printing press, it is possible to cope with variable printing in which the information of each printed matter is different for each sheet output by the printer.

[0020] The anti-counterfeiting printed matter formed by the above method has a high image change effect and high resistance to counterfeiting. Also, it can be manufactured by offset printing, which is a highly productive printing method, and has excellent cost performance. Also, it can be manufactured by digital devices such as printers, and the technology has high versatility. Since it can cope with variable printing when output by a printer, it can be applied to security printed matters that require personalization such as ID cards.

Brief Description of the Drawings

[0021] [Figure 1] Shows the anti-counterfeiting printed matter in the present invention. [Figure 2] Shows an outline of the configuration of the anti-counterfeiting printed matter in the present invention. [Figure 3] Shows the first image in the present invention. [Figure 4] Shows the second image in the present invention. [Figure 5] Shows the positional relationship of the fitting of the background element and the latent image element in the present invention. [Figure 6] Shows the effect of the anti-counterfeiting technology in the present invention. [Figure 7] Shows the emphasis element applied to the printed image in the present invention.

Embodiments for Carrying out the Invention

[0022] Embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below, and other various embodiments are included as long as they are within the scope of the technical idea described in the claims.

[0023] First, the present invention will be described with reference to the drawings. FIG. 1 shows an anti-counterfeiting printed matter (1) in the present invention. The anti-counterfeiting printed matter (1) includes a printed image (3) having a color different from that of the base material (2) on the base material (2). The printed image (3) represents the first significant information under diffused reflected light. In this embodiment, the first significant information is the letter "A" of the alphabet.

[0024] The printed image (3) is formed by fitting the first image (4) and the second image (5) shown in FIG. 2. The first image (4) is made of a luminescent coloring material, and the second image (5) is made of a coloring material having no luminescence of the same hue as the luminescent coloring material constituting the first image (4). Therefore, the hues of the first image (4) and the second image (5) are the same. In this specification, the hue refers to not only the so-called chromatic hues representing the appearance of colors such as red, blue, and yellow, but also achromatic colors such as white, gray, and black are included in one hue. That is, white, gray, and black are defined as having the same hue.

[0025] In this invention, "having lustrous properties" means having at least the effect of increasing brightness when light is incident on it, also known as light-dark flip-flop properties. Furthermore, when light is incident on it, it may not only increase brightness but also have color flip-flop properties where the hue changes. Light-dark flip-flop properties are generally optical properties possessed by glossy or shiny materials, while color flip-flop properties are optical properties possessed by functional inks such as pearl pigments and OVI (Optical Variable Ink).

[0026] Figure 3 shows the first image (4). The first image (4) comprises an information section (4A) and a background section (4B). The information section (4A) consists of information elements (4a) arranged in positions that do not overlap with the background elements (4b) of the background section (4B), and the presence or absence of these elements and the size of their area ratio constitute the letter "A", which is the first significant information. In this embodiment, the information elements (4a) are regularly arranged on both the upper and lower sides of the background elements (4b) with the same width (W2) and a specific pitch (P1) in the first direction (S1 direction). However, the arrangement is not limited to this, and they may be arranged in areas where there are no background elements (4b), and the presence or absence of these elements and the size of their area ratio represent the first significant information, and they may be composed of solid blocks, and there is no particular need for them to have any regularity.

[0027] One of the background parts (4B) is made up of background elements (4b) of a specific line width (W1) arranged regularly in a first direction (S1 direction) at a specific pitch (P1). In this embodiment, the background elements (4b) are made up of straight lines, but are not limited to this, and may be made up of dashed lines, wavy lines, etc., or pixels. In addition, the background elements (4b) are made up of white elements (4c) of a specific width (W3) arranged regularly at a specific pitch (P1). The white elements (4c) are the counterparts to the latent image elements (5a) that constitute the second image (5) described later. Furthermore, the white elements (4c) do not necessarily have to be completely white (area ratio 0%), and it is acceptable for them to have a certain area ratio as long as it is 50% or less. The relationship between the white elements (4c) and the latent image elements (5a) will be described later.

[0028] Figure 4 shows the second image (5). The second image (5) represents second significant information by regularly arranging latent image elements (5a) with a constant line width (W3) at a constant pitch (P1) in the first direction (S1 direction). The second significant information is information that appears in the printed image (3) under specular reflection. In this embodiment, the second significant information is the letter "B". The second image (5) consists of a non-glossy colorant of the same hue as the glossy colorant of the first image (4). Non-glossy means that it does not have light / dark flip-flop properties or color flip-flop properties. If it is to be formed with printing ink, it is desirable to use a low-gloss ink called a matte type.

[0029] Figure 5 shows the positional relationship between the first image (4) and the second image (5). The white element (4c) within the background element (4b) of the first image (4) and the latent image element (5a) of the second image (5) are positioned to fit together. Since the background element (4b) and the latent image element (5a) appear to be the same color under diffuse reflection, when the latent image element (5a) is fitted into the background element (4b), the latent image element (5a) is hidden within the background element (4b) and becomes invisible.

[0030] Here, specific examples of the iridescent colorant that forms the first image (4) and the colored colorant that constitutes the second image (5) will be described. In the anti-counterfeiting printed material (1) of the present invention, the characteristics are most effectively exhibited when silver is used for the iridescent colorant and black is used for the colored colorant. Silver and black belong to the same hue. Since black is generally 2 to 5 times darker than silver, the background element (4b) is composed of a halftone area ratio of 100% silver, and the latent image element (5a) is composed of a halftone area ratio of 50% to 20% black.

[0031] Silver is a colorant with excellent brilliance that consistently produces high reflected light in offset printing and printer output, while black (black ink) is a color used for text and designs in most printed materials, making it extremely versatile. In other words, since black is almost always a color used even without anti-counterfeiting technology, the only colorant that needs to be prepared solely for the formation of anti-counterfeiting technology is silver, which has brilliance. As described above, the combination of silver as the brilliance colorant and black as the colored colorant is ideal for constructing the anti-counterfeiting technology of the present invention. However, the colorants used in the composition of the present invention are not limited to silver and black, and combinations such as gold and reddish-orange, or gold and bluish-orange, may also be used.

[0032] The effect of the anti-counterfeiting printed material (1) created with the above configuration will be explained using Figure 6. When the positional relationship between the light source (6), the anti-counterfeiting printed material (1), and the observer (7a) is observed at an observation angle where diffuse reflected light is dominant, as shown in Figure 6(a) (an angle where the angle of incidence of light incident on the printed material (α) (45° in this example) and the reflection angle (β) connecting the observer and the printed material are significantly different (0° in this example)), the observer can see the letter "A", which is the first significant piece of information. Under this diffuse reflected light, the letter "B", which is the second significant piece of information, cannot be seen.

[0033] On the other hand, when the anti-counterfeiting printed material (1) is observed within an angle where specular reflection is dominant, as shown in Figure 6(b) (an angular range in which the angle of light incident on the printed material (α) and the reflection angle between the observer (7b) and the printed material (β) are close in value (in this example, both angles are 45°)), the letter "A", which is the first significant piece of information shown in the first image (4), completely disappears, and the letter "B", which is the second significant piece of information, becomes visible. Under this specular reflection, the letter "A", which is the first significant piece of information, is not visible.

[0034] The basic principle by which the two images of this invention change is as follows: At the observation angle where diffuse reflected light is dominant, as shown in Figure 6(a), the first significant information, which has a difference in density due to the difference in the image area ratio in the printed image (3), is visible. On the other hand, at the observation angle where specular reflected light is dominant, as shown in Figure 6(b), the first image (4), which is composed of luminous colors, specularly reflects the incident light and changes to a fainter state. As a result, the visual density difference in areas other than the second image (5) becomes relatively smaller, the gradation is compressed, and the first significant information becomes invisible. On the other hand, the color of the second image (5) does not change, and as a result, the second significant information represented by the second image (5) is visible under specular reflected light. This is the principle by which the image change effect occurs in the anti-counterfeiting printed material (1) of this invention.

[0035] In this invention, the angle in which diffuse reflected light is dominant refers to an angle in which specular reflected light is almost nonexistent and the proportion of diffuse reflected light is extremely large. The state of light at this observation angle is also called under diffuse reflected light. On the other hand, the angle in which specular reflected light is dominant refers to an angle in which diffuse reflected light is small and the proportion of specular reflected light is large. The state of light at this observation angle is also called under specular reflected light.

[0036] When fitting the white element (4c) of the first image (4) and the latent image element (5a) of the second image (5), redundancy in the printing process can be ensured by thickening the contours of the boundary between the two elements to cause them to overlap. The appropriate range varies depending on the density of the luminous and colored pigments, but specifically, an overlapping area of ​​about 0.01 mm to 0.10 mm may be provided. While a larger overlap makes printing easier, it reduces the opacity of the latent image element (5a), so it is necessary to keep it within an appropriate value depending on the density of the pigments.

[0037] Furthermore, in the anti-counterfeiting printed material (1) of the present invention, a third image (8) may be added to further enhance the change effect. This third image is an image that fills in the non-image areas of the printed image (3), and is a negative image in which the shading of the printed image (3) is reversed. By forming this third image (8) with a colorant that has light-dark flip-flop properties, the effect of the disappearance of the first significant information under specular reflection can be enhanced. The anti-counterfeiting printed material (1) of the present invention exhibits a high change effect when a highly glossy paper such as coated paper or art paper, or a highly smooth plastic, is used as the substrate (2), but the change effect tends to be lower when an uncoated paper such as general fine paper is used. This is because, in addition to the fact that the glossiness of the first image (4) is suppressed due to the low smoothness of the substrate (2) that serves as the base for the printed image (3), the substrate (2) exposed from the non-image areas of the printed image (3) produces the effect of making the first significant information visible under specular reflection due to its low gloss.

[0038] To address this issue, a third image (8) formed from a glossy, color-matched or transparent colorant to the substrate (2) can be used to fill in the non-image areas of the printed image (3), thereby eliminating the exposed areas of the substrate (2). Adding the third image (8) to the printed image (3) enhances the effect of the disappearance of the first significant information during specular reflection, allowing the first significant information to be expressed with a larger contrast (gradation range) than usual. This is more desirable because it increases the visibility of the first significant information and enhances the change effect.

[0039] If the substrate (2) is white, a white colorant should be used. A transparent colorant can be used with any color of substrate (2). In terms of optical properties, it is sufficient if it has a light-dark flip-flop property. As for the colorant, if it is a printing ink, a white ink or transparent gloss ink should be used, and if it is a printer, a white or transparent toner or ink should be used.

[0040] The lustrous colorant that forms the first image (4) is a colorant containing a lustrous material that has the property of strongly reflecting light, and any colorant can be used as long as it is a different color from the substrate. If the colorant is an ink, commercially available offset inks include metallic inks such as silver ink and gold ink, and pearl inks that contain special pearl pigments can also be used. In addition, it is not a problem to mix in coloring pigments in addition to the lustrous material. The color of the coloring pigment can be any hue, such as black, red, blue, or yellow. However, if an excessive amount of pigment is mixed, even if the first image (4) is formed within an appropriate dot area ratio range, the gradation expression range will be expanded too much, and the first image (4) may not completely disappear when observed under specular reflection. Therefore, in any case of mixing in coloring pigments, it is desirable to keep the amount not exceeding half the amount of the lustrous material in the ink.

[0041] The aforementioned lustrous material may be a common metal powder pigment such as aluminum powder, copper powder, zinc powder, tin powder, brass powder, or iron phosphide. Alternatively, a common pearl pigment such as iridescent pearl pigment or flake pigment, a functional pigment such as glass flake pigment or cholesteric liquid crystal pigment may be used.

[0042] The colored pigment that forms the second image (5) may have the same hue as the pigment that has luminescence. To achieve a high switching effect regardless of the substrate, it is desirable to use a matte pigment. This is because matte pigments tend to enhance the contrast of the second significant information under specular reflection, thereby increasing the image change effect. In addition, luminescent pigments such as fluorescent pigments, phosphorescent pigments, and phosphorescent pigments, as well as functional materials such as IR absorbing pigments, photochromic pigments, temperature-indicating materials, and thermochromic materials may be added to this colored pigment. In this case, various functionalities can be added in addition to the image switching effect.

[0043] The printing method for the anti-counterfeiting printed material (1) in this invention can be any printing method, such as offset printing, flexographic printing, letterpress printing, gravure printing, screen printing, and intaglio printing. Furthermore, if metallic ink can be used, it can also be formed using various digital output devices such as IJP, laser printers, and dye-sublimation printers, in which case so-called variable printing can be performed, where the information on each individual output is changed.

[0044] In this embodiment, binary images of alphabets were used for the first and second significant information, but the invention is not limited to this, and multi-tone images such as photographs or paintings may be used for each image.

[0045] The following describes in detail an example of an anti-counterfeiting printed material (1) specifically manufactured according to the embodiments for carrying out the invention described above, but the present invention is not limited to this embodiment. [Examples]

[0046] An embodiment of the present invention will be described using Figures 1 to 7, similar to the embodiment. In the embodiment, a general white color printer paper (J paper, manufactured by Fujifilm Business Innovation Co., Ltd.) was used as the substrate (2).

[0047] For printing the anti-counterfeiting printed material (1), a commercial printer (Fuji Xerox DocuPrint Cp310st) was used. This printer is a commercially available laser printer that can accommodate metallic toner. In this example, silver metallic toner, black toner, and white toner were used.

[0048] The first image (4) is created by first forming the letter "A" with a solid color (100% halftone area), then regularly overlapping background elements (4b) in line format with a line width of 0.2 mm at a pitch of 0.4 mm in the vertical direction, and finally placing white elements (4c) in positions that overlap with the background elements (4b). The white elements (4c) have a line width of 0.2 mm and are regularly arranged vertically at a pitch of 0.4 mm. The second image (5) is created by regularly arranging latent image elements (5a) with a line width of 0.2 mm at a pitch of 0.4 mm in the vertical direction.

[0049] The first image (4) was composed of silver, and the second image (5) was composed of black. Furthermore, experiments were conducted at multiple levels to determine the relationship between the halftone dot area ratios that maintain a color-matching relationship between silver and black using this printer. It was confirmed that a color-matching relationship is achieved when the silver halftone dot area ratio is 100% and the black halftone dot area ratio is 30%. Therefore, the first image (4) was formed entirely with a 100% halftone dot area ratio, and the latent image element (5a) of the second image (5) was formed with a 30% halftone dot area ratio. Additionally, the third image (8) was printed with white toner at a 100% halftone dot area ratio across all non-image areas of the printed image (3). This white toner was a colorant with a so-called light-dark flip-flop property, where its brightness increases by reflecting light. By printing a document with the above configuration using the printer, the anti-counterfeiting document (1) was completed.

[0050] Figure 6 illustrates the effect of the anti-counterfeiting printed material (1) of the present invention. Figure 6(a) shows the image observed when an observer views the anti-counterfeiting printed material (1) under diffuse reflected light, and the letter "A," which is the first significant piece of information, is visible in the printed image (3). On the other hand, as shown in Figure 6(b), when an observer views the anti-counterfeiting printed material (1) at a specific viewing angle under specular reflected light, the letter "A" disappears from the printed image (3), and instead, the letter "B," which is the second significant piece of information, is visible. Thus, the effect of changing between two different images was confirmed. [Explanation of symbols]

[0051] 1 Anti-counterfeiting printed matter 2 Base material 3. Printed image 4. First image 5. Second image 4A Information Department 4B Background part 4a Information element 4b Background elements 4c White-out element 5a Latent image element 6 light source 7a Observer 7b Observer 8. Third image

Claims

1. A printed image having a different color from the substrate is provided on at least a portion of the substrate, The printed image comprises a first image formed from a colorant having a lustrous quality and possessing a first significant piece of information, and a second image formed from a colored colorant having the same hue as the colorant having a lustrous quality under diffuse reflected light and possessing a second significant piece of information. The first image consists of an information section and a background section, the information section consists of a regular arrangement of multiple information elements, and the background section consists of a regular arrangement of multiple background elements and white elements. The second image described above consists of multiple latent image elements arranged in a regular pattern. The aforementioned white-out element and the aforementioned latent image element are fitted together, and the aforementioned background element and the aforementioned latent image element are formed with visually equivalent colors. An anti-counterfeiting printed material characterized in that, under diffuse reflected light, the first significant information can be made visible by the difference between the area ratio per unit area of ​​the background and the area ratio per unit area of ​​the information section and the latent image section, and under specular reflected light, the second significant information can be made visible by the difference in the reflective properties of the colorants.

2. The anti-counterfeiting printed material according to claim 1, characterized in that the lustrous coloring material is a silver coloring material, and the colored coloring material is a black coloring material.

3. The anti-counterfeiting printed material according to claim 1 or 2, having a third image formed of a colorant of the same color as the substrate or a transparent colorant, wherein the third image has a light / dark flip-flop property and is superimposed on all non-image portions of the printed image.

Images