Rosin is an ingredient in printing inks, photocopying and laser printing paper, varnishes, adhesives (glues), soap, paper sizing, soda, soldering fluxes, and sealing wax. Rosin can be used as a glazing agent in medicines and chewing gum. It is denoted by E number E915.
Pine Rosin is made from the oleo-resin (turpentine) harvested from various kinds of pine tree which is then boiled to remove the essential oils. This leaves a brittle solid ranging in colour from the lightest yellow to a deep red-black
Their most important uses are in the manufacture of adhesives, paper sizing agents, printing inks, solders and fluxes, various surface coatings, insulating materials for the electronics industry, synthetic rubber, chewing gums and soaps and detergents
A tea made from pine resin is supposedly good for arthritis as well. The resin or sap from pine trees has a variety of uses, most of which don't involve eating it.