Picture frame is decorative edging for a picture, such as a painting or photograph, intended to enhance it, make it easier to display, or protect it.
Picture frames have traditionally been made of wood, which is still the most common material, although other picture frame materials are also used, including silver, bronze, aluminum, and plastics such as polystyrene[polystyrene?:cnc ps/polystyrene cutting machine], though these require specialized equipment in order to cut. A picture frame may be of any color or texture, but gilding is common, especially on older wooden frames. Some picture frames have elaborate mouldings which may relate to the subject matter. Complicated older picture frames are often made of moulded and gilded plaster over a plain wood base. Picture frames come in a variety of profiles, but generally the lengths of moulding feature a "lip" and rabbet, the function of which is to allow a space to hold in the materials in the frame.
