A security-enhanced document including a substrate, variable indica applied to an area of a first side of the substrate, a scratch-off-coating applied over the variable indicia to maintain the variable indicia unreadable until the scratch-off-coating is removed by being scratched off, and digital imaging applied to an area of a reverse side of the substrate from the variable indicia, wherein the digital imaging applied to the area of the reverse side of the substrate includes the same materials as the variable indicia, is uniformly spread over the area of the reverse side of the substrate, and such that the digital imaging overlaps at least 50% of the variable indica applied to the area of the first side of the substrate, such that the variable indicia exhibits an insufficient signal-to-noise ratio relative to the signal-to-noise ratio of the digital imaging on the reverse side of the substrate so that the variable indicia cannot be discerned so long as the scratch-off-coating remains intact.

Disclosed herein is an electrostatic ink composition comprising a component selected from a fatty acid ester having a plurality of hydroxyl substituents and a fatty acid amide having a plurality of hydroxyl substituents. Also described herein are scratch-off structures and methods for producing them.

A gimmick expression medium producing method forms a gimmick expression medium 300. The gimmick expression medium 300 includes a retroreflective medium 1. A printing medium 301 placed on the retroreflective medium 1 includes a light-transmission layer 302. A gimmick print 303 which varies color of reflective light of the retroreflective medium 1 to produce a gimmick effect is printed on the light-transmission layer 302. The printing medium 301 is provided with a light-blocking layer 304 which partially blocks reflective light reflected by the retroreflective medium 1. The light-blocking layer 304 is composed of a white printing layer, and a reflection picture print 305 is printed on the light-blocking layer 304. The reflection pattern printing 305 and the gimmick print 303 are placed in adjacent to each other using a stripe-shaped (or dot-shaped) lattice pattern 306, printing which can be seen on a printed matter under normal illumination and printing which can be seen under light source such as flash light can be printed at one time (one-pass) by the same printer.

A security-enhanced document includes a substrate and variable indicia comprising ink having a signal. The variable indicia is of a specific type and is applied to the substrate using a specific application technique. At least one other printed portion, which is a back of the document, has background ink noise, and the type of ink of the back of the document is of the same type of ink applied to the substrate using the same application technique as the ink of the variable indicia. The document also includes a scratch-off-coating applied over the variable indicia. The document has a signal-to-noise ratio of the ink of the variable indicia relative to the background ink noise of the back of the document that is not appreciable, thereby making the variable indicia unreadable with reference to the back of the document when the scratch-off-coating remains intact.

A method includes printing, by one or more printer heads of the printing system, a reactive layer onto print media. The method also includes printing, by the one or more printer heads, a determined number of transmission layers and a determined number of barrier layers in alternation with one another. At least a portion of the reactive layer is configured to migrate through the transmission layers. The method further includes printing, by the one or more printer heads, a reactant layer that is configured to change color responsive to a reaction that occurs between the reactant layer and the reactive layer upon migration of the reactive layer through the determined number of transmission layers. The reaction is configured to occur on a received expiration date.

A color changing expiration indicator includes a reactive layer and a first barrier layer that covers at least a portion of the reactive layer. The color changing expiration indicator also includes a transmission layer that covers at least a portion of the first barrier layer, and a second barrier layer that covers at least a portion of the transmission layer. The color changing expiration indicator further includes a reactant layer that covers at least a portion of the second barrier layer. The reactant layer changes color responsive to a reaction that occurs between the reactant layer and the reactive layer.

In one example of the disclosure, a substantially transparent substrate is provided at a printer. A primer layer is applied upon a first surface of the substrate. A security ink layer that includes security information is applied upon the primer layer. An opaque background ink layer is applied upon the security ink layer. A corona treatment is applied to a second surface, located on an opposite side of the substrate relative to the first surface. A release ink layer is applied upon the corona-treated second surface. An opaque cover image ink layer is applied upon the release ink layer.

A printer system includes a memory, a processor, and one or more printer heads. The processor determines a number of transmission layers and a number of barrier layers to use in a color changing expiration indicator based at least in part on a time period between a print date of the indicator and a received expiration date. The printer heads print a reactive layer onto print media, where at least a portion of the reactive layer is configured to migrate through the transmission layers. The printer heads also print the determined number of transmission layers and the determined number of barrier layers in alternation. The printer heads print a reactant layer that is configured to change color responsive to a reaction between the reactant layer and the reactive layer upon migration of the reactive layer through the transmission layers. The reaction is configured to occur on the received expiration date.

A method includes printing, by one or more printer heads of the printing system, a reactive layer onto print media. The method also includes printing, by the one or more printer heads, a determined number of transmission layers and a determined number of barrier layers in alternation with one another. At least a portion of the reactive layer is configured to migrate through the transmission layers. The method further includes printing, by the one or more printer heads, a reactant layer that is configured to change color responsive to a reaction that occurs between the reactant layer and the reactive layer upon migration of the reactive layer through the determined number of transmission layers. The reaction is configured to occur on a received expiration date.

In one example of the disclosure, a substantially transparent substrate is provided at a printer. A primer layer is applied upon a first surface of the substrate. A security ink layer that includes security information is applied upon the primer layer. An opaque background ink layer is applied upon the security ink layer. A corona treatment is applied to a second surface, located on an opposite side of the substrate relative to the first surface. A release ink layer is applied upon the corona-treated second surface. An opaque cover image ink layer is applied upon the release ink layer.