Caring for your Stretched Canvas
There are a few basic precautions you can take to make sure your stretched canvases are kept in the best condition possible. Follow these guidelines and you'll have nothing to worry about!
The best way to store your stretched canvas is upright against a wall. Unpainted or completely dry canvases should be placed back-to-back and front-to-front. Watch out when leaning smaller canvases against larger canvases as denting can occur.
If you stretch your canvas yourself, it's best to work in an area with as little humidity as possible. Canvas fibres tend to react to moisture by becoming shorter, so if you stretch in damp conditions, the surface will lose its tension when the fibre dries out.
What to do in the case of...
All canvases can crack around the edges. This is due to pressure on the edges while stretching or, in some cases, because the top surfaces of your primer have become brittle. On a well-primed cotton or linen, cracking will effect only the surface layers of priming, and the quality of the fibre itself will not be affected because it is protected by a layer of rabbit skin glue or a synthetic clear size. At worst, edge areas with cracking will have increased absorbency, which can be corrected by brushing on an extra coat of primer by hand.
Slack or rippled canvas
If your canvas slackens out or forms ripples, it is more than likely that the fibre has responded to a decrease in moisture levels by lengthening slightly, relaxing the tension on the frame. The first thing to do is to try tapping in the wedges with a small hammer. If this doesn't work, lightly and evenly spray the back of the canvas. In dire cases it will be necessary to have your canvas re-stretched.
It's common for oil-primed canvases to yellow when they are not exposed to daylight. The linseed oil in the primer tends to discolour in the dark, but don't worry, it will brighten up again when exposed to sunlight.
Changing the surface
If you are not happy with the consistency of your primer, to smoothen, sand back evenly with rougher sandpaper and then add another layer of primer. Repeat until you're satisfied with the surface.