M. Graham's Walnut Oil and Walnut Alkyd mediums were developed to provide artists with a non-toxic, environmentally friendly alternative to solvent-based, fast-drying alkyd mediums. Walnut Oil mediums closely resemble many characteristics of sun-thickened oils and natural resins typically used with oils but do not necessitate harmful solvents. After drying, Walnut Oil mediums remain flexible; over time, they will not yellow as much as linseed oils.

Brushes can be cleaned during and after painting with walnut oil, followed by a final wash with mild detergent if painting is not resumed for several days. There is no need for harsh thinners or turpentine for clean-up, which reduces the disposal of harmful chemicals and unnecessary pollution. Walnut oil effectively removes colour from artists’ brushes and is a natural vegetable oil that does not evaporate or strip essential oils from the brushes. Adding walnut oil to paint will slow drying, enhance flow, and increase sheen.

The walnut oil medium is intended to enhance the unique qualities of our oil colours while remaining fully compatible with other artists' oil colours and mediums.