Natural Pigments refined aged linseed oil is a low-acid value drying oil pressed from North American flaxseed. This is as light and pure as industrially-produced linseed oil can be made. Use to grind colors, thin oil colors or prepare varnishes.Linseed oil is a yellowish drying oil derived from the dried ripe seeds of the flax plant (Linum usitatissimum, Linaceae).