Michael Harding Refined Walnut Oil dries at the same rate as linseed oil, but it does not yellow as much. Michael Harding use it as the binder for their lead whites where the brightness of the colour demands the clearest possible oil binder, without compromise on production costs. Use it to thin whites and to bring out the brightness in other colours.

The use of walnut oil in paint can be traced back even further than that of linseed. When 15th century artists began to add oil to their tempera colours it was walnut oil that seemed the obvious choice. Jan van Eyck in Flanders and Antonello da Messina in Italy both knew of its handling properties.