Daler rowney masking fluid is the ideal solution for protecting areas of watercolour artworks from washes of water based colour it can be used to create striking white highlights or areas for overpainting at a later stagethis fluid forms a fast drying water resistant film on water colour paper or board easily removed when dry by rubbing with an eraser soft tissue or cotton bud an old brush pen or cotton bud should be used to apply the masking fluid as it is extremely difficult to remove fr