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: 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.