Rosin is a solid resin derived from the oleo-resin (crude turpentine) exuded by various species of pine tree. Rosin is extracted by heating the oleo-resin to vaporise the essential oils (spirit of turpentine), or through a naphtha solvent process. Rosin is mainly produced in Portugal and Brazil but Indonesia, northern Vietnam, southern China, the US, Mexico and France are also producers. Rosin is sold as a semi-transparent solid ranging in colour from yellow to black and has a faint odour of pine. The commercial grades range from A (the darkest) to K (yellow red), M (yellow brown) and N (deep yellow), through to superior WG ("Window Glass", yellow) and WW ("Water White", slight yellow).
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