http://www.liquitex.com/GelMediums/

Liquitex is a brand of artist materials, focusing exclusively on the development, manufacture, and distribution of acrylic paints. In 1955, the company known as Permanent Pigments, founded by Henry Levinson, created the first water-based acrylic paint, along with the first acrylic gesso. At this time, Levinson reorganized the company as Liquitex. In 1956, the company developed colored liquid acrylic paints. Liquitex offers the widest acrylic paint product line in the world.