Glossary: How to stretch a canvas

A canvas is traditionally supported by a wooden stretcher consisting of 4 mitre bars that interlock to form a rectangle or square. The top outside edge has a  slightly chamfer to accommodate the canvas which is then laid over the stretcher and attached with picture tacks. This leaves the canvas with some slack which is taken up by the insertion of 8 wooden stretcher pegs that are hammered into ready prepared slots in the 4 corners. In the case of large paintings two central bars are added to give the stretcher strength. The canvas is now ready for use.