Sheet film manufactured by Kodak had notches cut into the side. The notch patterns could be decoded by touch in absence of any light. The code would tell you if the film was Tri-X, Plus-X etc.
Sheet film manufactured by Kodak was regular base or Eastar base. Eastar base was thicker, and would accept re-touching pencil on either side.
3x4 Film could be contact printed on 3x4 glass lantern slide plates, for spectacular sized projected images.
