Real Milk Paint ® is best applied to porous surfaces like raw wood, unprimed drywall,  concrete, brick, terra cotta, unglazed tile, cinder blocks, and more. If you’re working over surfaces that already have a finish, are metal, plastic, or painted with an oil-based paint then we typically recommend our Ultra Bond to add to the milk paint. As always, prepping the surface is the most important step to painting and proper preparation will produce the best results with any paint.