Slight resinous matter (rust) and slight amounts of dry mould on wrappers, bale surfaces and interior sheets, found at the time of delivery will not be objected to. Should “rust” or “dry mould” in an appreciable extent appear on more than 20% of the bales sampled, it shall constitute grounds for rejection. Medium sized bark particles, bubbles, translucent stains, slightly sticky and slightly over-smoked rubber are permissible to the extent as shown in the sample. Oxidized spots or streaks, weak, heated, under-cured, over-smoked (in excess of the degree shown in the sample) and burnt sheets are not permissible. The rubber must be dry, firm and free of blemishes, blisters, sand, dirty packing and all other foreign matter other than those specified above as permissible.