Purpose : Temporary masking of sections in a water colour painting Composition : Dispersion of natural rubber in water Prevents adhesion of water colour to areas of the painting that are treated with Liquid masking film Dries in 10 minutes Once dry remove with the fingertips or an eraser within a few days Becomes more difficult to remove after some time Can cause discolouration on cellulosic paper Can also be used for water-based inks