This spring I found this screenprint of a ship at a thrift store in Sooke. It's by Howard Smith and printed by Vallila of Finland. I don't know where it was living before I found it, but it looked like it might be a leaky cabin with a chain-smoking knife thrower. It was ripped, yellow, and badly mounted onto a broken frame. I'd been looking for a canvas print to put above my son's bed and this seemed perfect, so I looked into restoring it. I took the cheap option, because it's all we needed. But here are additional tips and sources should anyone want to restore a canvas. Someday, I expect I will look this up again, myself:
Professional restoration — If your piece is valuable, it's best to take it to a professional, like Fraser Spafford Ricci. For a larger canvas (3 x 2 feet) you can expect to pay between $700 – $1,000, but that will make it like new(ish). I spoke with them on the phone and they gave me some tips about cleaning. Their process for canvas involves a special chemical solution that you cannot buy. They have large rolls of cotton wool, like large q-tips that they gently roll over the surface of the canvas.
Drycleaning — screenprinted canvas is different than screenprinted linen. You cannot wash or dry-clean it. If you think it might be linen, you can cut off a test strip off the side and send it to a good drycleaner's. I cut off a damaged area along the side and my dry cleaner tested it with a few solutions (it didn't work).
Surface dirt — it isn't as time-consuming as it sounds, it's maybe 20 minutes a day for a week. Lay out the canvas on a large, flat clean surface and have a bowl of cotton wool (or big facial wipes — I think Shiseido facial cotton would be perfect, because it is quite large) and another bowl with a mild ph balanced soap, like baby shampoo or Eucalan. Keep the water well away from the canvas — it can permanently damage it. Wet a cotton ball and squeeze it out. Gently rub or roll over a section of the surface of the canvas — start with an area you can cut off if it damages the print or canvas. If you get the canvas wet, it will permanently buckle, so you want the cotton wool to be damp, not wet. When your cotton wool begins to look dirty, throw it away and get a new one. This is really boring, I listened to This American Life while I did it.
When you have done a whole pass of the canvas, let it dry. If you can, let it dry flat in the shade or hang it outside in the shade. Fold one end (as short as possible) over the line and use several clothespins so it doesn't stretch too much. If there isn't shade, you can hang a thin piece of cotton or linen over it, to protect it from the sun. You will have to do this a few times and it won't get it all off, but it should brighten it and make it smell better. I alternated sides.
Cigarette smoke — this was the big one for me, because it was to go in my son's bedroom. Each time I washed the surface with the cotton balls and the canvas was very slightly damp, I sprinkled the canvas with a ton of baking soda. I left it for half an hour before putting it out to dry. Once it was dry, I gently beat it to shake it all out. The canvas doesn't smell at all like smoke now. The professional cleaner I spoke to said that baking soda does not help with cleaning.
Water damage — water damage (that big patch on the upper left area) doesn't come out without professional help. I decided it was a big fog-covered sun, and it doesn't bother me now :)
Tears — There's a tear in the canvas. I was going to have it invisibly mended, but I had a hard time finding a good invisible mender (the one I used to use is closed — email me if you know a good one in Vancouver). I decided to leave it and if I ever find a good mender I might bring it in. When we had it stretched for a new frame, the framer handled it so it wouldn't stretch and tear further.