Some polymers that are formed in a mould are self-finishing, meaning that the inside surface of the mould is so smooth that the form that is taken from it is also smooth. A motorbike helmet is a good example - the outside of the helmet is smooth because of the mould it was made in.
Once a polymer has been cut or shaped from its original stock form, the edge that has been cut can be rough and will need to be finished. Using acrylic as an example:
Vinyl cutters can be used to cut sheets of self-adhesive vinyl, which can be used for signs on cars, vans and shop fronts. The sheet vinyl is available in many colours and is bought on a roll. A vinyl cutter is a computer-controlled machine - the cutting tools moves along vector paths, which have been set out within the design. Long signs can be cut as the vinyl is on a roll that feeds into the machine.