Method of distinguishing between the front and rear of a developed film

摘要

One side of a developed film (transparency) consists of an emulsion layer, and the other side of a base layer. The two layers have different water contents. The front and rear of the film can be distinguished from one another by altering the water content of the emulsion layer by heating or wetting of the film and detecting the state of curving, in particular the direction of curving, of the film after altering the water content.