Winsor & Newton Oil Painting Primer is a ready-to-use primer in a non-yellowing oil-modified alkyd resin medium. No thinning or stirring is required. Oil Painting Primer can be applied directly to metal or porous surfaces (glue-sized canvas, untreated wood, hardwood, plywood, paper) with virtually no sinking in. A small amount of oil colour can be mixed into the Oil Painting Primer for tinted priming. The treated ground then accepts oil colours easily and without chalkiness or absorbency.