Turpentine is an organic product that is steam distilled from the resin of pine trees of many varieties. The better resins come from the Eastern Seaboard English Pine because of the saltiness in the air.
Producing turpentine: A pine tree is stripped of its bark in a V-shape. The remaining trunk will begin to secrete a resin, called OLEORESIN, which then travels down the trunk and funnels to the V-shape. The secretion is a protective measure the tree performs to prevent exposure and sap loss. The Oleoresin is collected and mostly steam distilled in a copper still. The oily residue that forms is used as a solvent that we call turpentine.
The two major conventional uses of turpentine are to thin oil-based paint or to produce varnish.
As a decorative painter, I use it primarily to create an oil-based glaze. I use the cheap stuff (gum turpentine) to thin alkyd varnish, which really helps achieve an ideal viscosity. But I primarily purchase the artist-grade English distilled turpentine for my oil glaze. See my OIL GLAZE RECIPE
What’s the difference between turpentine and paint thinner? Turpentine has a higher degree of oil content; therefore it mixes with linseed oil better and creates a greasier mix.
!! WARNING: When mixing turpentine with linseed oil, a combustible formula is created. Exercise extreme precaution and proper cleaning techniques. The mixture can cause a huge fire if left on a dry rag or cotton gloves. Submerge your soiled rags in water and/or stretch them out to prevent a cozy cavern for combustion.