Rutile Titanium Dioxide Advice: Recommended for exterior (outdoor) exposure or where long term light fastness BT-R20 Sulfate treated with a combination of alumina, silica and/or zirconia that useful in master batch/plastic/rubber, PVC and much more. Content% 91.5min PH Value 6.0-9.0 Oil Absorption(g/ 100g ) 23min Packing: 25kgs/bag BT-R21 Sulfate treated with alumina and zirconia, that widely used in highway marking/traffic,prinking ink. Content% 91.5min PH Value 6.5-9.0 Oil Absorption(g/ 100g ) 19min Packing: 25kgs/bag BT-R22 Sulfate treated with zirconia and alumina. Suitable for PVC, film laminating, latex paints,rubber/masterbatch/plastic,paper making. Content% 92min PH Value 5.0-8.5 Oil Absorption(g/ 100g ) 21min Packing: 25kgs/bag