When you want the freedom to apply broad colour washes across your painting surface but do not want the wash to cover key details within a composition, Art Masking Fluid can help.
Unlike Permanent Masking Medium, which is intermixable with watercolours, you apply Art Masking Fluid directly to the paper. It can be used on white paper or previously coloured areas, and it acts like skin over those areas you want to protect from the colour wash. Once you have finished applying the colour wash you can simply remove the masking fluid.