Developed by Sennellier & Pablo Picasso, Sennelier Artists Pastels contain more Pigment than any other brand. Use on a Variety of Surfaces including Canvas, paper, metal, Wood, stone, even glass. Create multi-media effects over oil, acrylic, pastel or Watercolor. These pastels can be thinned with turpentine are lightfast non-toxic and acid-free to resist drying. Choose from 120 open stock Colors. WARNING: This Product contains a chemical known to the state of California to caUse cancer. (Unbound Titanium Dioxide)