Historically, letterpress printing, in some form, was the dominant process from the time multiple copy printing began until the 1960's. Offset lithography is the dominant process used currently in the printing industry. In modern offset printing, metal plates have been substituted for the stone, with ink dispensing roller systems, dampener rollers to wet the plate, and a paper handling system for either sheet or roll stock. Gravure or intaglio, as the process is sometimes called, involves creating recessed images in a suitable plate material, filling that recess with ink so that none remains on the raised surface, then putting a substrate in contact under pressure to transfer the ink from the recess to the substrate. Screen-process printing is sometimes erroneously called silk-screen printing. This stems from the fact that originally the woven fabric that supported the image forming material was silk. Currently, the support screen is made of various types of synthetic woven materials and some metal screens include stainless steel. The screen is stretched tightly on a metal or wooden frame that not only holds the mesh firmly but also provides a dike in which the ink can be applied and forced through the mesh onto the material being printed. Areas of the screen are blocked out selectively with a masking material that can be applied by hand or through the use of photosensitive resists. The raised image processes described are steel-die engraving and thermography. Guidelines are provided for distinguishing between the various printing processes when examining the printing on a document. 18 figures, 1 table, and 13 references