Rosin is an ingredient in?printing?inks, photocopying and laser printing paper,?varnishes,?adhesives?(glues),?soap,?paper?sizing,?soda, soldering?fluxes and?sealing wax. It can be used as a glazing agent in medicines and chewing gum. In industry, rosin is a flux used in soldering. A mixture of pitch and rosin is used to make a surface against which glass is polished when making optical components such as lenses.