Contents copyright 2005 Davis Multimedia Intl. Inc. all rights reserved.
The following information is presented here courtesy of The Engravers Journal. More information may be available by visiting the EJ web site (www.engraversjournal.com) and checking out EJ’s archive of articles (1975-present). Key word searches may be performed using the EJ Index of Articles, and most back issues (1975-present) are available.

PHOTO METALS—OVERVIEW

Photo metal is a specially designed metal (usually aluminum) which contains a subsurface coating of a silver halide photo emulsion. The emulsion is sensitive to UV light so that when it is exposed, utilizing a high resolution film negative to define the image area the silver halide emulsion undergoes a latent chemical change in a manner similar in principle to traditional balck and white photography. The processing of a photo metal plate then involves utilizing a chemical (photographic) developer, followed by a "fixer" application, and finally a "sealing" operation which closed the pores. The resulting black mark contrasts with the aluminum background.

When properly processed and sealed, a photo metal plate is very durable, and is resistant to UV light and many chemicals, including salt water, etc. The image remains sealed below the surface.