Golden Acrylic Medium : GAC 100 3.78litre : a universal acrylic polymer for extending colour This polymer is one of the most universal used in paint manufacturing. Artists who had used "Rhoplex" (a registered trade name) will find that this GAC most closely reflects the properties to which they were accustomed. The GAC 100 is a useful polymer for protecting against Support Induced Discoloration (S.I.D.). The most flexible with a moderate level of tack and gloss. Useful for diluting and extending colors, especially when film flexibility and integrity are important characteristics. Wets pigment surfaces well. The most ideal for artists formulating their own paints.