Color reversal film - Reversal film, or transparency, has the same tri-pack construction as negative film but involves an extra step in the creation of a positive image from the negative. The developed negative image is briefly 'exposed' so that the silver compounds that had remained unaltered now form reverse, positive images. After a second color development, the silver is bleached away and three color layers are left which give the effect of the original subject colors. See also Non-substantive film.
