Abstract: Laminate document include line screen patterns for authenticating the documents. The line screen patterns can hide information in the documents that can be revealed by a viewer. Print densities of the line screen patterns can be adjusted to compensate for effects associated with lamination. A built-in viewer can be spaced from the line patterns to shift image intensity or color through rapid cycles of moire interference with changes in viewing angle.

Abstract: A document and a related viewer for the document are constructed as image files capable of transmission to a printing site. The document file contains information for printing a document having hidden security indicia, and the viewer file contains information for printing a document viewer having a decrypting portion for revealing the hidden security indicia in the document.

Abstract: Copy protections are incorporated into print media by embedding a plurality of latent images formed by different line-screen patterns within a visually integrated setting formed by another different line-screen pattern. The different line-screen patterns of the latent images have line frequencies empirically selected so that upon reproduction at least one of the latent images is rendered more readily discernable to the unaided eye. A masking design formed by another line-screen pattern overlies both the latent images and the visually integrated setting.

Abstract: A document comprising a latent security image that is visible when the document is reproduced after being scanned by a standard commercial bank scanner. The security image comprises a plurality of lines, dots, or spots having a frequency and a density such that the image is reproduced after being scanned by the standard commercial bank scanner. A method of making a reproducible document comprising a security device comprises generating the document by creating an original containing the security device, scanning the original to a digital computer using a conventional scanner, and converting the scanned original to a digital image file which is printable via a digital press, a color copier, etc. A document comprises a security image that is not visible under ordinary light, and is visible when the document is exposed to a predetermined type of light. The security image is printed with an ink visible under one of UV light, infrared light, X-rays, of Gamma rays.

Abstract: A latent image is incorporated into an apparent solid-color background for representing a desired solid-color background having a target color. An underlying solid-color background is printed on a print medium using a first color composition that differs from the target color. Line-screen patterns embedding a latent image in a visually integrated setting are printed over the solid-color background using a second color composition that differs from both the first color composition and the target color. The visual characteristics of the line-screen patterns forming the latent image and the visually integrated setting are matched for rendering the latent image practically indistinguishable from the visually integrated setting without a visual aid. The print densities of the line-screen patterns and the first and second color compositions are interrelated so that the line-screen patterns in combination with the underlying solid-color background produce the apparent solid-color background in the target color.

Abstract: A security image embedded in an original printed document survives a conversion process into an image replacement document in binary image form having a commercial equivalency with the original printed document. The security image is embedded in a background at an approximately common visual density with the background so that the security image is at least partially indistinguishable from the background to the naked eye. Print elements of the security image are arranged differently than the print elements of the background and both are further arranged so that that upon conversion into the image replacement document in binary image form, the security image survives and the background drops out.

Abstract: A compound security feature is formed by printing latent images together with visually integrated settings using an invisible ink. Even if illuminated by a wavelength capable of rendering the inks visible, the latent images remain visually indistinguishable from their visually integrated settings. However, the latent images and visually integrated settings differ in one or more less obvious ways so that the latent images can be distinguished by using a visual aid.