Marshalls Photo Oils are transparent oil colors specifically designed for tinting black-and-white photographs by hand. Highly concentrated and intermixable, they offer superior adhesion on photo paper. Theyre also acid-free and archival to ensure the long-term stability of your artwork. - Marshalls Photo Oil Color - Background Gray Blue, 1/2" x 2" TubeMarshall Photo Oil, GRYD BKGND BLU .5X2 -