Super stiff extremely responsive flexible silicone synthetic bristles that hold a high volume of paint while providing smooth application. The true advance in Catalyst is the Polytip feature. For the first time the tip of each individual hair has been split to replicate the natural flags on the finest natural bristle. By giving each individual hair 2 to 3 distinct tips Catalyst is able to hold a higher volume of paint while providing a smoother application. Designed for heavy-body acrylics and mediums but can also work with oils acrylics water miscible oils plaster clay and even frosting. Heat-resistant for encaustic work as well. Easy to wipe clean and solvent resistant. Long handle short filbert 12.