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