The canvas tension of any Winsor & Newton stretched and primed canvas should be suitable for painting on without the use of the wedges.

But after a period of time either after or during painting, the tension of the canvas could become loose. If this occurs, the tension can be regained by fitting the canvas wedges that come with each Winsor & Newton canvas. Here’s how to do it:

1. Insert the wedges by hand into the corner slots, in the orientation shown.
2. Place pieces of card between the stretchers and the canvas in each corner. This protects the canvas from any accidental contact during wedge fitting.
3. Stand the canvas upright.
4. Using a small hammer, knock the wedges upwards into the slots while supporting the canvas with your free hand.
5. Always use the wedges to move one stretcher at a time, thus keeping the canvas square.
6. Rotate the canvas and continue to knock the remaining wedges with the hammer until the desired tension is reached.

How to fit canvas wedges diagram
Diagram showing positioning of wedges within stretched canvas.