Black natural rubber gaskets are cut from rubber sheets or mould pressing. Any sizes and shapes can be produced. The hardness of natural rubber gasket ranges from 40 to 60 durometer, Shore A. Die cut natural rubber gaskets are generally tan or black in color with the exception of our premium grade “red” gum natural rubber, which is used when an optimum combination of tear and abrasion resistance are required. Natural rubber gaskets are available with or without pressure sensitive adhesive backing.