Water based formula, use with brush or pen. Liquid Mask is used to reserve areas which are to remain unpainted, especially in airbrush techniques, but also with watercolours and temperas. The product forms a protective film on the area which the artists does not want to paint. Once the work is dry, liquid mask is rubbed off with an eraser or piece of cloth, revealing the unpainted area. Shake lightly and test on surface before use. Do not leave applied for a long time. To remove, peel or rub carefully once dry. Keep from freezing. Warning! Contains natural rubber (Latex), may cause sensitization by skin contact.