Temporary masking of sections in a water colour painting. 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