Colophony, also known as ROSIN or RESIN, is a solid form of RESIN obtained from coniferous trees. It is used in a variety of applications, including as an ingredient in varnishes, adhesives, and soldering fluxes. It is also used in the production of paper, printing inks, and rubber products. Colophony has a long history of use in musical instruments, where it is used to increase friction between the strings and the fingerboard.