Hygroscopic refers to a substance’s ability to absorb moisture from its surroundings. Being highly breathable, Claypaint is a hygroscopic paint that will ‘even out’ the humidity in a room by absorbing excess moisture. It’s especially suitable for older properties and rooms that have suffered with damp, as it lets the walls breathe. Being hygroscopic, the surface of Claypaint will change and the colour may deepen where it has absorbed moisture. When allowed to dry out naturally these marks should disappear, although in some cases, for example if there are salts in the walls, some staining may occur.