Although ‘acrylic’ has become a generic term for any synthetic paint medium, acrylics are a specific type of manmade polymer that has become standard in the commercial paint industry as well as widely used by artists from the mid-20th century; most synthetic paint media in contemporary artistic use are based on acrylic emulsions. Acrylics are thermoplastic, have great optical clarity and excellent light stability, good adhesion and elasticity and resist ultraviolet and chemical degradation. Their unique surface properties, transparency and brilliance of colour, together with the possibilities they offer for indeterminacy, immediacy, randomness and the ability to rework immediately and to achieve extremely thin or thick surfaces, are qualities that have been exploited fully by such painting movements as Abstract Expressionism in the 1950s, and, subsequently, colour field painting, hard-edge painting and Pop art.