Spike oil is a natural, low-toxic substitute for turpentine. It can be used as a solvent for oil painting and in egg-oil emulsion tempera recipes. It was used historically in oil painting as early as the fifteenth century. It is believed that spike oil improves the handling of oil-based paints, because it promotes oxidation instead of simply evaporating like most solvents. However, this has not been verified by scientific testing. A small amount goes a long way and it has a pleasant smell unlike other solvents. It evaporates slower than turpentine, mineral spirits (white spirits) and odorless mineral spirits (OMS).