Designer Liner is clay based and heavily pigmented. Use this versatile product to create fine detail with lines, dots, and letters. The metal writer tip allows for ultimate control to draw ultra-fine or bold lines, typography and intricate illustration, or apply with a brush to create watercolor or ink wash effects. Designer Liner is best when used under non-moving transparent or semi-transparent glazes. Designer Liner will fire matte when glaze is not applied over top. AP Certified Non-Toxic and dinnerware safe when clear glaze is applied. Fires from cone 06-10, with little change in performance between firing temperatures