1. a) These standards are concerned with both raw stock for permanent record films and with the processed films ready for storage. They are not restricted to microfilm but apply equally to motion picture films, roll films, and sheet films. They reflect incorporations listed in Section 4400.22.
2. b) All such film stock shall be of approved permanent type polyester based film that includes an anti-halation dye system that meets the minimum specifications of ANSI/AIIM MS23.
3. c) Each frame of microfilm shall be exposed and processed so that every line and character on the document appears on the microfilm with sufficient clarity to permit reproducibility through three successive generations of reproduction. With regard to operational procedures, inspection, and quality control of silver gelatin microfilm, ANSI/AIIM MS23, shall apply.

4. d) The background photographic densities must be appropriate to the type of documents being filmed. Appropriate background densities are as follows:

   Classification	Description of Documents	Background Density
   Group 1	High-quality, high-contrast printed books and periodicals; black type face; fine-line originals; black opaque pencil writing; and documents with small, high-contrast print.	1.00 to 1.30
   Group 2	Pencil and ink drawings; faded and very small print (for example, footnotes at the bottom of a printed page); scenic checks; documents with printed pictorial images; and newspapers.	0.90 to 1.10
   Group 3	Low-contrast manuscripts and drawings; graph paper with pale, fine-colored lines; letters typed with a worn ribbon; poorly printed, faint documents.	0.80 to 1.00 (1:24 reduction or less)
   Group 4	Very low-contrast (worse case) documents can require extremely low background density.	0.75 to 0.85 (1:24 reduction or less)
   Group 5	COM	1.50-2.00

(Source: Amended at 39 Ill. Reg. 3031, effective February 11, 2015)