Gum Rosin/Colophony/Natural Rosin/China Gum Rosin/Resin gum rosin has been general used for ink, adhesive, paint, food ... manufacturing of paper, paint, soap and printing ink. Since rosin is easily softened and oxidized, in the oil paint ... ink, resin acid is changed into disproportionate rosin, polymerized rosin, hydrogenated rosin, etc for further use by its double bond reaction. China Gum Rosin