Ad Reinhardt's work became increasingly reductive and symmetrical in the 1950's and from 1955 until his death he worked almost exclusively in near-black. In fact the blue-black surface of 'Abstract Painting No. 5' has an underlying grid of different coloured squares divided by a green central horizontal band. Seen from top left, the squares are: red, blue, red, red, blue, red. Each of these colours was mixed with black oil paint to give a matt surface quality.