Other contributors have said "What are the two natural fibres?" is the same question as "What are the four natural fibres?" If you believe that these are not asking the same thing and should be answered differently, click here
natural fibers are fibers gotten from natural sources like cotton. Natural fibers could be from both animal or plant sources. They are therefore classified under protein and cellulose fibers. They...
Denim itself is not a fibre... Denim is a fabric which is mostly commonly made out of cotton fibres (which are natural). However today much more denim is being made from a cotton-synthetic fibre mix.