MM28 Polymer Satin Varnish is used as a final varnish over a dried, well-cured acrylic painting when a satin or very mid level sheen is required Polymer water-based varnishes may appear to be slightly hazy whilst in solution. This is an optical effect produced by light refraction of acrylic particles suspended within the water-based medium. The effect disappears when the film is dry. As acrylics dry very rapidly, care should be taken to apply varnish pre-diluted with water. Polymer Varnish, applied in very thick layers on a hot day, could trap moisture, resulting in a cloudy film which would be very difficult to correct.