Bipack color

Bipack and three-element tripack sandwiches of plates and films were used in some early color processes for still photography, the field in which the concept originated.

Bipack photography refers to two strips running through the camera at once, for the purpose of recording two different spectra of light, generally.

No filtering is necessary either for exterior or interior photography, as all necessary color corrections are made by adjusting the development of the two negatives during printing.

After processing the two negatives, the red and cyan records were printed separately on a single strip of Eastman or DuPont duplitized stock.

Over the years, a great number of bipack color processors existed, largely due to the lack of holding patents on processing in this method.