Rosin, also called colophony or Greek pitch, is a solid form of Pine oleoresin from pine trees, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black. At room temperature rosin is brittle, but it melts at stove-top temperatures. It chiefly consists of different resin acids, especially abietic acid.

Rosin was identified as gum rosin, wood rosin, tall oil rosin. Gum rosin appears yellow color such as the picture. Gum Rosin from Indonesia is a natural organic compound, derived from Oleo Pine Resin. It is a yellowish solid vitreous product resulting from the distillation of Oleo Pine Resin.

Gum rosin are used for the manufacturing of paper, paint, soap and printing ink. Since rosin is easily softened and oxidized, in the oil paint industry, the carboxylation reaction of resin acid is usually employed to produce resinate for further use. While in the producing of synthetic rubber and printing ink, resin acid is changed into disproportionate rosin, polymerized rosin, hydrogenated rosin, etc for further use by its double bond reaction.