The white colored pigments that color paints pastels chalks and other art materials. There are 2 main types of white pigment, the opaque ones used mostly as paint colorants, and the semi transparent types used in gouaches, but also as fillers and extenders in some paints. Titanium dioxide has become by far the single most important white. It is opaque and non-toxic and colors all kinds of paints and drawing materials. Health concerns have virtually eliminated the use of lead white usually known as Flake White or Cremnitz White. Zinc White still is found in Gouaches and watercolors. Chalk is a pigment that is white when dry, but almost transparent when wet and is used in gouaches to make the colors more opaque. Other White pigments that can only be described as fillers or adulterants include Blanc Fixe, Gypsum, Alumina Hydrate, Kaolin and many others.