Shoe Maker Question:

ISNR 20 (TSAR 20) is general purpose rubber graded by precise technical standards and not by visual characteristics. Some standards may vary marginally based on the origin. Technically Specified Rubber (TSAR) is used for making tires, tubes, rubber mats, cushion gum stock, raincoat proofings, micro-cellular sheet for upholstery and packing, conveyor belts, footwear and various other rubber products.