This work is one of a number of paintings made between 1958 and 1962 which have been described by critics as ‘atmospheric’ non-figurative paintings. Heron has filled the canvas with colour in an all-over composition which does not contain one single focal point. He explores the depth of the picture space by using layers of partially hidden, coloured shapes and creating form through variations of colour. The rectangles appear to be both floating on top of and emerging from the surface of the painting. Although the painting is not intended to be directly representative, the colours and shapes suggest a sun setting on the horizon.