A word used in the production of artists’ materials. It is binding action of a paint vehicle in which the pigment particles are completely contained within a film.e.g. like it is in oilpaint or acrylics. It best understood by its opposite. In watercolours the binding action simply glues together the pigments and leave them as a sediment rather than inside an enveloping film. The effect of watercolours is refereed to as cementitious.