The solid, brittle, clear resinous residue left after the distillation of turpentine from balsam, having a color ranging from yellow or reddish-brown. It becomes sticky when warm and has a faint pine-like odor. Primarily composed of abietic acid (about 80%), rosin reacts in hot alkaline solutions to form rosin soaps. Rosin weathers poorly, becoming oxidized and brittle with age. It also has poor moisture resistance. Although many of its aging properties are undesirable, rosin is or was used as an ingredient in paints, varnishes, inks, adhesives, sealing wax, soldering fluxes, sizing paper, and linoleum. Because it increases sliding friction, it is commonly used for coating bows of some stringed instruments, and as a slip preventative on the floors of stages and shoes of dancers. The inexpensive resin is also used for sizing paper.
