This oil pastel is acid-free, so there is no need to prime any surface as a preventative barrier for protection against deterioration from acid. The neutral pH mineral wax provides a remarkably creamy texture that will never harden or yellow, thus providing excellent adhesion to any support, without fear of cracking. The oil pastel may be thinned with spike lavender oil, turpentine, or mineral spirits to make washes or soften drawing strokes, or blended with the Transparent Blending Medium stick for a wide array of effects.