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Stephen Tashiro
12-02-2009, 12:06 PM
Has any artist and Creeker been able to stretch artists canvas over plywood and prepare it the normal way with gesso ?

(I'm talking about "stretching", i.e. stapling the canvas only at the edges, not gluing the whole canvas down. "Gesso" , pronounced like Jess-oh, is essentially a thick white water based acrylic paint The traditional way to mount canvas is to stretch it over a wooden frame that has a beveled edge. This frame is called a "stretcher", which distinguishes it from a "picture frame". Only the edges of the final painting touch the stretcher. I mount 1/2 inch quarter round moulding on 1"x2" stock with the flat side of moulding facing the outside of the picture to achieve this effect.)

For pastel drawing, I wanted to have a canvas that was supported on its entire surface. So I tried stretching a linen canvas over a 2 ft by 2 ft sheet of 1/2" birch plywood as an experiment. (There was no moulding on the plywood, the canvas lay flat on the sheet.) The canvas looked flat after 1 coat of gesso. After a light sanding and a second coat, it raised up in places. I think this is because the first coat of gesso glued the canvas to the plywood as the canvas shrank. The sanding pulled it up in places.

I unmounted the canvas. I sanded the plywood smooth. I turned the canvas around so the gessoed side faced the plywood and re-stretched it. You can put already gessoed canvas on a stretcher, so I thought this would work. But after two coats of gesso and a light sanding between them the canvas again developed raised spots.

Is there something fundamentally flawed about stretching canvas over plywood or will a different method work?

A traditional internet answer to the question "How do you do this?" is "You don't want to do that?" or "You don't have to do that!". Both those answers may be true in my particular case, but answers about stretching plywood would of interest to artists in general.

Some reasons why are:

I may simply glue to the canvas to the plywood, but "serious" artists want their work to last for generations. When wooden
stretchers deteriorate, a canvas can be removed and remounted on a new stretcher. It is a much worse job to pull up canvas that has been glued to a board. Furthermore, chemicals in glue may attack the canvas.

I may mount canvas on a stretcher and use a temporary piece of plywood set behind it as a support. The disadvantage to this is that you tend to get lines at the edge of the plywood when you draw with pastels

I do not want to draw on un-gessoed canvas because I want to apply water based acrylic paint for color and a water based primer to give the surface the traditional sandpaper finish that is used for pastel drawing. Unstretched canvas would wrinkle. Even the sheets of canvas sold in pads will wrinkle. They are only gessoed on one side and water getting to the back of the sheet shrinks it in places.

Brian Brown
12-02-2009, 2:08 PM
Stephen,

I had the perfect answer until I read this.


I may mount canvas on a stretcher and use a temporary piece of plywood set behind it as a support. The disadvantage to this is that you tend to get lines at the edge of the plywood when you draw with pastels


Is it possible to take a small piece of matte board say 8 X 20, and slip it between the canvas and steatcher frame, in an area where you are working, then back the whole thing with a sheet of plywood under the canvas and matte board? The matte board will keep the lines from appearing where the gap is in the plywood, and it can be moved from area to area as you work. It doesn't sound very convienient, but I think it would work. If you are painting all the way to the edge of the canvas, just slip it back out, and finish the edge with the streacher as a backer.

What ever you do, I wouldn't glue the canvas to the plywood anywhere. There are chemicals used in the processing of plywood that will leach into the canvas causing severe damage. That is why streacher frames are made of untreated wood rather than a composite material. A lot of artists that bring paintings to me for copying, paint directly on tempered masonite, and I always wondered why they are not concerned about the same problems.

Most of the pastel artists I have worked with use a canvas glued to an illustration type board. Reputable companies make them with archivally stable adhesives. I know that this limits your canvas size options, but it is better than a deteriorating masterpiece. Good luck in your search, and you might try some of the artists forums. The pastel artists must have run into the same problem.

Sean Hughto
12-02-2009, 2:19 PM
My father is a professional painter. I grew up in his studio. He paints with acrlics on canvas. He sometimes paints with large canvases stretched on the "floor" - a horizontal plywood platform covered with very low pile indoor outdoor carpeting (the carpet is stapled/stretched in place), and more often lately paints on canvas stretched on plywood sheets covered with indoor outdoor carpet. When dry, the painting is removed from the floor or the plywood sheet and stretched on a typical stretcher built to fit the painting. The carpet keeps the bleed through paint (gesso in your case) from sticking the canvas to the wood.

Stephen Tashiro
12-02-2009, 4:21 PM
Those are some useful ideas. Sometimes I do use a thin board of to support various places on a canvas If I could mate the edge of the support to the shape of the quarter round, I could slide the board all the way to the edge of canvas. If the board covered, say, 3/4 of the canvas, I could shift it around where I needed it. An imitation of the carpet method would be to mount the canvas temporarily on plywood or plywood with a pad over it, draw and paint the picture, take it off and put it on a stretcher.

Stephen Tashiro
12-04-2009, 9:52 PM
After some thought, for my next experiment I want to put something around the edge of the plywood to raise the edges a fraction of an inch. Over the face of the plywood, the canvas would be touching only along the edges. Canvas stretches when you draw on it so it would get pressed against the plywood temporarily as you drew. I need only enough clearance between the plywood and the canvas to keep the gesso from sticking them together.

What I need is some simple way to put a shallow, narrow raised edge around the plywood. Is there something simple that would do that? An edge about 1/16 th wide and 1/16 th inch tall would be my first guess. I could almost use thick wire, if I had a way to attach it along the edge of the plywood. What are some other methods?

Caspar Hauser
12-05-2009, 4:58 AM
Attach a thin strip of wood or aluminium to the edges of your plywood, a little thicker than your plywood to leave a little lip, stretch your canvas, stapling/tacking to the back of the ply.

Or. temporarily stretch canvas on a larger piece of polyed/waxed or plastic wrapped ply, prime, draw and paint, then re-stretch to the desired smaller size, or. temporarily stretch pre-primed canvas on a larger piece of ply, draw/paint, then re-stretch to the desired smaller size.

Alternatively Gesso poplar panels, fish, rabbit or hide glue gesso, six or seven coats, scraped not sanded, lasts hundreds of years.

Stephen Tashiro
12-05-2009, 2:04 PM
Attaching aluminium to the edge is an interesting idea. I worry that an average job of attaching it to a 1/2 inch plywood might not hold up since the canvas is stretched across the sides and tugs on them. Perhaps I have to build a wooden frame and rout out the members so the plywood will sit down inside it.

Caspar Hauser
12-05-2009, 5:40 PM
How big a canvas are we talking about?

John Coloccia
12-05-2009, 5:57 PM
If the whole problem is the canvas sticking to the plywood in places where it shouldn't, I'm thinking a very simple answer is to simply staple a layer of plastic before applying the canvas. I'd probably try the thinnest vapor barrier available at the Borg (polypropylene, I think). Even Saran wrap might work.

Stephen Tashiro
12-05-2009, 6:52 PM
That might work. To make sure the "scenario" is understandable, let me repeat about the gesso. The canvas is painted with what amounts to a thick white acrylic paint and a little of this paint seeps through the threads to the back of the canvas. The point is not to have the canvas stuck to anything. If it was stuck to the poly in places, it might wrinkle. (I'm not positive that it would wrinkle. Your idea is worth trying.) When canvas is first stretched over a stretcher it usually has small wrinkles. The gesso (or any water based coating) makes the canvas shrink and pull tight.