When an artist wishes to paint on canvas, usually the canvas is stretched on a supporting frame structure comprised of a generally rectangular framework having four wooden side members. If the canvas is not stretched sufficiently or evenly along all four sides, waves or ripples are created in the canvas which make it unsuitable for use by the artist.
Various types of mounting and stretching devices exist which are used to tension canvas mounted on a frame. However, these devices, especially if they are adaptable to canvas of different weights having different stretching requirements, are expensive, often complicated to use and overly complex. Usually, they include some sort of clamping device for grabbing a free edge of the canvas and then spring or biasing means which are brought into play on the canvas which rely on the expertise of the user or a recalibration for every canvas weight and frame size. A typical prior art canvas stretching device is shown in U.S. Pat. No. 4,180,246.