Inside Out Library · ExploreHydron blue G and R, patented paste 20% and powder (1911)Cassella Color Company · New York · leaf 3021 23 25 AFTERTREATED WITH SULPHATE OF COPPER. 26 28Dyes and dyeingInternet Archive · Clark Art Institute Library · Public Domain Mark 1.0. Free to use for anything.More pictures from Hydron blue G and R, patented paste 20% and powderMore like this
