Synthetic thermoplastic polymer used for molded items, sheets, films, and fibres. FTC (U.S. Government) classification is Olefin. The polymer is made by stereo specific polymerization of propylene. Most polypropylene carpet fibre is solution dyed and sometimes contains ultraviolet stabilizers for outdoor use. Printable modifications are available but not extensively used. The carpet fibre is available as both bulked continuous filament yarns and staple for spun yarn production.