Four-color gum bichromate prints

Four-color gum bichromate print The gum bichromate is a printing process that has had its peak in the late nineteenth century and early twentieth century. It is a contact printing process in which the negative must have the same final image size. The image is formed on a sheet of paper for watercolor where it is applied with a brush a mixture of arabic gum, pigment and potassium bichromate. The sheet is exposed, in contact with the negative, to the rays of a UV mercury vapor lamp .To get real colors I shoot these still lifes with four selection filters: red, green, blue, yellow, receiving four black-white negative and then I print every negative with complementary color; color photography was invented in this way.