After the break-up of the „Brücke“ group in 1913, Heckel had step by step found his own painting style, a more moderate Expressionism. This is also evident in his choice of colour, which are somewhat more muted, without a loss of expression.
In 1922 he was commissioned to paint a whole room in the Angermuseum in Erfurt with a mural in secco technique. “Lebensstufen“ (Stages of Life) is the only surviving mural by a „Brücke“ artist.
That year Heckel painted a number of watercolours which show his wife Sidi sleeping. The artist lets the viewer share an intimate moment, which he has depicted with great sensitivity.