“Dye Destruction” colour printing systems.

Gasparcolor was one of several “dye destruction” direct positive printing systems that used a tripack film with three layers sensitive to red, green and blue that already incorporated cyan, magenta and yellow dyes. A positive image was exposed onto the film. The negative silver image produced by development was used to initiate the destruction of the coated dyes, resulting in a subtractive colour positive. Gasparcolor is not unique, there were a number of patents issued for these processes, and Cibachrome is a modern still colour paper print material. Although in theory the process could have been used for a camera original film the dyes coated in the emulsion reduce the photographic speed to very low levels.