scope:

This specification covers cardboard mounts for large transparencies. These mounts are intended to be used with type 1, size C overhead projectors conforming to Fed. Std. No. 73 and Federal Specification GG-P-661.

Mounts shall be of the following types, styles, and mask apertures, as specified (see 6.2).

Type I - Roll glazed pressboard (permanent mounts). Type II - Calendered pressboard (permanent mounts). Type III - Railroad board (semi-permanent mounts).

Style A - Fileable in letter size cabinets Mask aperture 7 ½ by 9 ½ inches (for 8 ½ by 10-inch film). Mask aperture 7 ½ by 10 inches (for 8 ½ by 11-inch film). Mask aperture 8 by 10 inches (for 8 ½ by 11-inch film). Style B - Fileable in legal size cabinets Mask aperture 5 ¼ by 8 inches (for 8 by 10-inch film). Mask aperture 7 ½ by 9 ½ inches (for 8 by 10-inch film). Style C - Fileable in special cabinets or store flat in legal size cabinets. Mask aperture 7 ½ by 9 ½ inches (for 8 by 10-inch film). Mask aperture 8 by 10 inches (for 8 ½ by 11-inch film). Mask aperture 9 by 9 inches (for 9 ½ by 9 ½-inch film). Mask aperture 10 by 10 inches (for 10 ½ by 10 ½-inch film). Mask aperture 7 ⅝ by 9 ⅝ inches (for 8 by 10-inch film).

intended Use:

These mounts are intended to facilitate handling, projecting and filing of large transparencies.