Natural rubber (rough surface) is for general usage and good in water resistance and for general water piping gasket. However natural rubber might not be good choice if the application need to be resistance to Ozone, whether, oil, solvent and chemical. Natural Rubber available in form of Sheet and Gasket with different sizes of thickness and measurement.
Some better/heavy duty grade Natural rubber is excellent in physical strength & tear and abrasion resistance, which usually use in mining industry.
Inquiry - Natural Rubber Sheet