Winsor & Newton Permanent Masking Medium is a non-removable, water repellent liquid wax that is designed for masking specific areas on paper, making them resistant to water. When dry, the medium will repel superimposed washes. Allow the medium to dry completely before overpainting. It is ideal for isolating areas of fine detail, simply apply directly to the paper or tint with small amounts of water colour. This will enable you to create unique special effects and fine details.75mlNon-removable water repellent liquidExcellent for detailApply directly to the paper or tint with small amounts of water colourAllow to dry completely before overpaintingWinsor & Newton Permanent Masking Medium 75ml