 The following year he filed a patent listing various color developers and dye couplers, which have historically been used in Agfachrome and are still in use today in Fujichrome Velvia and Provia, and Ektachrome.In spite of this, Fischer never created a successful color print due to his inability to prevent the dye couplers from moving between the emulsion layers.This first solution to this problem, found by Agfa workers Gustav Wilmanns and Wilhelm Schneider, who created a print made of three layers of gelatin containing subtractive color dye couplers made of long hydrocarbon chains, and carboxylic or sulfonic acid.