Acrylic varnish. Water based satin varnish improves the qualities of resistance to ageing of acrylic colors, unifies the differences in brightness of the picture and increases the depth of color. When the color is applied thickly, it is advisable to wait 1-2 weeks before varnishing work. Water-based acrylic varnish is covering and non-yellowing. They offer a perfectly taut film, that is flexible and indelible.