Winsor & Newton Galeria Extender increases the volume of acrylic paint while maintaining original colour opacity. Perfect to use when you want to extend a colour to cover large areas. Dries to a matt finish, Winsor & Newton Galeria Extender will resist yellowing. Winsor & Newton Galeria Mediums and Varnishes are a highly economical range for those who have limited budgets. Use with Winsor & Newton Galeria Acrylic Flow Paint.