Oil paint very slowly, darken, and crack, unlike mastic and wax (the latter of which was used in encaustic painting). Greek writers such as Aetius Amidenus recorded recipes involving the use of oils for drying, such as walnut, poppy, hempseed, pine nut, castor, and linseed. When thickened, the oils became resinous and could be used as varnish to seal and protect paintings from water. Additionally, when yellow pigment was added to oil, it could be spread over tin foil as a less expensive alternative to gold leaf. Early Christian monks maintained these records and used the techniques in their own artworks. Theophilus
Metro Fuel Oil Energy plans to process 100% renewable biodiesel which can be blended with heating oil or diesel fuel. The plant will employ technology that will enable United Metro Energy to capture and utilize waste generated by the process. The plant is scheduled to open in Third Quarter 2012. United Metro Energy was founded in 1942 when Pauline Pullo recognized that home heating oil was a cleaner, more efficient alternative to coal in the heating fuel market. United Metro Energy remained a relatively modest retail operation until, in the late 1970s, when Paul J. and Gene V. Pullo, Pauline’s grandsons, took over