Winsor & Newton Watercolour Colourless Art Masking Fluid creates a temporary cover to protect areas of work when you’re creating watercolour washes. This clear version is made with rubber latex, it can be applied with a brush (though be careful to clean it immediately) and dries to a film that is easy to peel or rub off when dry. It shouldn’t be applied to damp paper. Winsor & Newton Watercolour Colourless Art Masking Fluid is an excellent addition to any watercolourist’s kit.