gum rosin ww grade, resin, pale yellow We have a long-term stable supply channels and production base, quality assurance. Gum rosin is a natural ... the process conforms to China national standard(GBB145-87). Gum Rosin ww grade, resin Used in paper, ink, rubber, paints and varnish, various ... .030.030.04Ash content%≤0.020.030.04best regards, gum rosin