The second sequel in this series of articles concerns essential oil varnishes consisting of solutions of different resins in volatile oils as used up to the beginning of the 19th century. The most common essential oils are oil of turpentine and spike oil (an inferior type of oil of lavender). Until the 17th century petroleum or a distillate similar to white spirit often served as solvents. Even to this date, essential oil varnishes are used as varnishes for paintings. However, they cannot be polished like the spirit lacquers described in the first sequel, because they do not attain their hardness. -- AATA