The Homage to the Square series of paintings for which Albers is best known for were produced between 1950 and 1976. The format of these paintings consists of three or four nested squares placed weighted towards the base. The idea of the squares was to demonstrate the way solid colours visibly change according to the colour that surrounds them. Albers applied the paint straight from the tube with a palette knife on to masonite (hardboard) panels which he described as ‘platters to serve colour’. He used colour as a metaphor for human relationships, wanting his work to be seen on an informal and intuitive level, not as rigid visual geometry. The photographs and photo-collages include portraits of the artists Paul Klee and Wassily Kandinsky as well as records of his travels in Europe and Mexico. Not only do they capture biographical moments of Albers life but they also point to the same principles and lines of enquiry as his paintings: the exploration of the potential of tonal relationships, light and perception – what Albers called ‘poetry through scientific means’.