The first character position indicates the ratio range. Otherwise, specific ratios are optional. If you do not enter the specific ratios, enter three hyphens in the second, third, and fourth positions. The color characteristics of the microform. The type of film emulsion of the microform.
Silver halide is a compound of silver and halogens.
Silver halide microforms are black and transparent. Most commercial microforms are silver halide. Diazo is sensitized layers composed of diazonium salts that react with couplers to form dye images. The color of the image is determined by the composition of the diazonium compound and the couplers used in the process. The image may be black, violet, or another color.