Photocopy in the context of "Certified copy"

The Kodak verifax is a photo copying approach that uses a wet colloidal diffusion transfer technique patented by Yutzy, H.C. and Yackel, E.C. (1947) The light source is projected to the top crossing the negative being reflected -more or less, according to the color- against the original to be copied exposing the negative. Has a base that contains the recipient with the liquid developer and the exposure timer.

Due to its extreme simplicity, the method was commonplace until the late 1960s, when it was surpassed by the popularity of the xerocopies using plain paper. Copies had some chemical smell and lost contrast over time.

Microprinting is the production of recognizable patterns or characters in a printed medium at a scale that typically requires magnification to read with the naked eye. To the unaided eye, the text may appear as a solid line. Attempts to reproduce by methods of photocopy, image scanning, or pantograph typically translate as a dotted or solid line, unless the reproduction method can identify and recreate patterns to such scale. Microprint is predominantly used as an anti-counterfeiting technique, due to its inability to be easily reproduced by widespread digital methods.

While microphotography precedes microprint, microprint was significantly influenced by Albert Boni in 1934 when he was inspired by his friend, writer and editor Manuel Komroff, who was showing his experimentations related to the enlarging of photographs. It occurred to Boni that if he could reduce rather than enlarge photographs, this technology might enable publication companies and libraries to access much greater quantities of data at a minimum cost of material and storage space. Over the following decade, Boni worked to develop microprint, a micro-opaque process in which pages were photographed using 35mm microfilm and printed on cards using offset lithography. (U.S. patent 2260551A, U.S. patent 2260552A) This process proved to produce a 6" by 9" index card that stored 100 pages of text from the normal-sized publications he was reproducing. Boni began the Readex Microprint company to produce and license this technology. He also published an article A Guide to the Literature of Photography and Related Subjects (1943), which appeared in a supplemental 18th issue of the Photo-Lab Index.