Modern screens are made from a fine polyester mesh, stretched on a metal or wooden frame. A simple line stencil is cut using a digitally controlled pen plotter that manipulates a knife. More complex stencils and halftones can be made using a film positive as in lithography. The screen is coated on both sides with light-sensitive polymer emulsion and exposed through the film with ultraviolet light, after which the image areas are washed away with water. The screen is mounted on the press and a rubber-edged squeegee forces the ink through the mesh, passing only through the ‘open’ image areas. Though fine screens are available, screen printing is not recommended for close registration or work involving very small type sizes.