Whether we paint pet portraits, family portraits, landscapes, or house portraits, we all like to suppose our pictures will bear the test of time. Using a high calibre linen, that is correctly prepared with many layers of gesso on both sides and stretched over kiln-dried hardwood stretchers, they can last a lifetime . However, with the best will in the world, it doesn’t matter how well you prepare a canvas, it will always be vulnerable to damage through accidental pressure on the canvas causing dents or even rips in the surface. Such damage does not need to be disastrous for the painting and, in most cases, a damaged canvas can be repaired.

If accidental pressure on the canvas causes a lump, it can be removed by softly rubbing the area on the back with a wet finger. If this does not do the business, more moisture can be dabbed onto the canvas with a sponge, but be careful not to make the canvas too wet. Distortions can be rectified using a cool iron over the back of the canvas. Where pressure on the canvas has in reality caused the paint surface to crack, ironing from the back can reduce the appearance of the damage.

Small tears and punctures are repaired by adding a patch of the same type of canvas to the back of the picture. The patch should be at least 2 inches bigger on all sides than the tear itself, and frayed around the edges to mask it’s presence. The traditional adhesive for this is beeswax or beeswax and damar, with the patch being applied with a iron that is barely hot enough to melt the wax. There are new alternatives to this adhesive but be certain that only conservation quality ones are used.

Whenever you try to make any of these repairs, always make sure that the canvas is set face down on a flat surface and supported by a blanket covered with brown craft paper.

After a while canvases can become lax, if this occurs, do not automatically tighten the wedges as minor distortions are very likely to correct themselves. If the wedges do need tightening, avoid driving them in any more than is absolutely necessary, otherwise you run the risk of cracking the paint and cheap commercially prepared canvases may also rip. Canvases should always remain on the stretcher, if they are removed for any length of time, the canvas will relax making it difficult to re-stretch. If it does become necessary to remove the canvas from the stretcher, perhaps for transportation, paintings should always be rolled so that the paint surface is on the outside, as there is less risk of the surface cracking.

Picture renovation is a extremely skilled business and those who practice it have had many years experience in this field. The advice offered here is chiefly aimed at the artist wishing to repair his or her own works, anybody wanting to repair a valuable work should always take the painting to a professional picture restorer.