Polypropylene

A lightweight synthetic fibre that absorbs essentially no water at all, so it dries almost instantly and is used for base layers, sock liners and inexpensive tote bags. Its zero absorbency makes it the best wicking fibre there is, but also means it holds odour and cannot be dyed after it is made — colour has to be added to the polymer before the fibre is spun. It has a very low melting point, which is the decorator's warning: standard cure and press temperatures will melt or distort it, so polypropylene goods need low-temperature methods and a test piece first.