streaks of resin (resin) on spruce

streaks resin spruce gum sap galipot turpentine barrois soft dip nature oleoresin virgin balsam barras gallipot fir firtree picea black common pine oil rosin medicinal balms forestry forest science timber industry cupping tapping turpentining chemical boxing soaps varnishes paints paper making products macrophotograph photomacrography