For use with Watercolour this Daler-Rowney Simply Art Masking Fluid is used to create striking white highlights or areas for overpainting at a later stage. It forms a fast-drying water-resistant film on watercolour paper or board and is easily removed when dry by rubbing with an eraser soft tissue or cotton bud.For use with Watercolour.Suitable for all conventional art surfaces.Fast-drying and water-resistant.