Image development of overhead transparencies.

摘要

An overhead transparency system which enhances the density of images printed on film by ink-jet techniques is provided. The film is coated with a layer of a transparent, hydrophilic material to a thickness which promotes controlled lateral diffusion of the printed ink. The lateral diffusion is microscopically observed to begin within 1 minute after printing, eventually ceasing as the vehicle of the ink is sufficiently spread and evaporated by the lateral spreading. The optical density of the image increases as the ink diffuses, reaching a maximum density that is considerably greater than otherwise possible without an ink-coating system. Sheets of such printed transparencies are protected by insertion between sheets of a vapor permeable, water absorbent material such as cellolose acetate.