Breathing Color Timeless/G2 Varnish is designed to coat printed matte canvas and fine art paper manufactured by Breathing Color. For any other manufacturer, we strongly recommend coating a test piece with a small sample of our varnish before coating larger pieces, as we cannot guarantee compatibility. Breathing Color's Satin and Glossy coated canvasses like Crystalline, 17M, and Silverada do not need to be varnished. For photo papers, acrylic spray varnish is recommended over Timeless/G2