Sheet Film, Negative Images: on either acetate base or polyester base 4"x 5", 5"x 7" & 8"x 10"
B/W or Color
Master Image/Preservation Duplicate/ and Service Copy
Sheet Film, Positive Images: on either acetate base or polyester base 4"x 5", 5"x 7" & 8"x 10"
B/W transparency or Color Transparency
Master Image/Preservation Duplicate/ and Service Copy
Roll Film, Negative Images, typically cut into Strips: on either acetate or polyester base
B/W 35 mm (6 frames) or Color 35 mm (6 frames)
Master Image/Preservation Duplicate/ and Service Copy
B/W 2 1/4" (4 frames) or Color 2 1/4" (4 frames)
Master Image/Preservation Duplicate/ and Service Copy
Roll Film, Positive Images, cut and mounted, producing Slides: on either acetate or polyester base
B/W Slides 2" x 2" or Color Slides 2" x 2"
Master Image/Preservation Duplicate/ and Service Copy
Ideally a Master Image, Preservation Duplicate and a Service Copy exist for each image on film. In the large film collections at the Library of Congress only certain collections of highest value or rarity can be maintained this way.