Applying a coat of wood preserver to my garden shed is a task that is not likely to generate aesthetic excitement. Yet today as I removed green encrusted lichen I became aware of the subtle colour contrasts in the weathered wood. There were subtle contrasts of grey and green which made quiet harmonies that could be used as the basis of colour composition in a painting. It was important to make a note of them to aid memory. When the work was done I used pastel as a quick medium too record the effects I had observed.