Holbein Acryla Gouache is brilliant, lightfast and permanent. Made with a pure water soluble acryl resin, Acryla Gouache dries waterproof, opaque and absolutely matte. Traditional gouache is made with a gum arabic binder, causing it to have a very fragile paint film. Since Acryla Gouache is acrylic based, it develops a tougher, yet visually delicate, paint film. Allow 30-45 minutes of working time.