Glossmark™ technology is a digital watermarking process that embeds a visually striking gloss image within a high quality color print without the need of a special paper or toner. It utilizes the angular dependence of image gloss to create a differential-gloss image through the modulation of halftone structures. Both the primary image and the embedded Glossmark™ image can be distinctively viewed from different perspectives with little interference. The strong directional nature of the gloss and the subtle halftone modulation process make Glossmark™ images very difficult to detect by a scanner and even more challenging to reproduce through scanning and printing. Its distinct visual effect which is highly desirable for security printing makes it stand out among various halftone modulation technologies. Its differential gloss appearance which originates from the image surface roughness modulation offers better protection against counterfeiting than technologies that utilize only “plain” halftone modulations. Well-designed quality Glossmark™ images are optical variable devices (OVD's) ideally suitable for document authentications. Its digital implementation provides a capability to embed variable data as digital watermarks into individual prints quickly and economically.