Tightening key
 |
A corner key or tightening key is a small wedge or block of board, timber or plastic, inserted into the slotted inside corners of a canvas stretcher frame to prevent or adjust sagging.
Use
The piece is tapped in to expand the stretcher bars slightly, tensioning the canvas. The keys can be used to re-tighten the canvas as it relaxes naturally over time. Tightening keys are commonly made in plastic or wood, and are commonly known as corner keys or corner wedges.
Types
Corner keys or wedges come in various forms. Most are available for a single size stretcher bar, making framers and artists hold various sizes in stock. A product called "wedgee" eliminates the need to stock many types as it has a male / female profile which allows it to be pressed together to fit most corner cut-outs.
See also
 | This article related to art materials is a stub. You can help Wikipedia by expanding it. |