# A doubt on preparing a canvas for oil painting.



## Arduy (May 31, 2020)

Hello to everyone. I've got a doubt: up until now I've prepared my standard industrial primed canvases with acrylic gesso. I use oil colors on cotton canvases. Lately, I heard about an artist who primes the canvas even on the back side of it, in order to prevent absorption of humidity from the back of an untreated canvas. Could this artist be right? I think it could make sense, but I'm unable to find any other information on the subject, so I posted here for some help. Thanks for your time.


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## newbie (May 14, 2020)

Thanks for posting your query. Now I am curious too to know. Hopefully some expert on this forum may help.


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## Desta Art (Jun 4, 2020)

Hi Arduy. I haven't seen or heard of an experiment that covered a primer on the back of a canvas preventing or helping anything. At least what I know in my experience are Two negative things. 1 Covering on both sides Adds more expenses. and 2. Usually after the painting is done. when for all sorts of reasons the canvas is loose or erect you can splash water and rub it and stretch it back. the intent. This leaves direct access to canvas. Besides, don't forget most of the reference materials we use go through all kinds of experimentation over the years. This is why we also use all kinds of primers or colors designed for professional painting. And not industrial materials.


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## Arduy (May 31, 2020)

Thanks for your replies. I searched again for some more information about the subject, and I found some very useful thoughts from some people:
From https://www.wetcanvas.com/ 
User: Freesail
1. You should never apply gesso to the back of the canvas, it needs to breathe.
2. What you really should have done prior to painting was apply more gesso to the front of the canvas.
User: Ron Francis
1. Certainly old paintings that have been sealed on the back have not faired well, but these were not sealed with acrylic gesso rather than sized with hide glue and then painted with oil.
Other users say that the important thing is to prepare the front of the stretched canvas really well.
From https://www.quora.com/
User: Marcus Lim
1. When we decide to use canvas for oil painting, the most important area to prepare is the painting surface. We all know its importance with protecting the fabric from the corrosive effects of the oil medium. So, preparation with rabbit skin glue or any modern primer is priority. This will do away the need with priming the back side of the canvas, to serve the purpose.
User: Beth Goldowitz
1.	If the canvas has been properly primed, either with rabbit skin glue (old school) or acrylic gesso (modern). then that’s all you need do to protect it. Paintings prepared this way last for hundreds of years. 
User Kathleen Grace
1.	The back of the canvas needs to remain as is - do not prime, do not seal. The painting breathes, and if you cut off the air supply you may end up growing mold between the layers, as well as creating competing sides which will expand and contract at different rates. 
User Marc Clamage
1.	If the canvas has been prepared correctly, it is not necessary protect the back of the canvas in any way. If I may, the only serious threat to the back of the canvas is the front of the canvas. If the canvas has not been suitably sized and primed, the oil will leak through and rot the canvas. In that case, taking steps to preserve the back of the canvas are not going to do you much good.
So, it seems that I should not do anything to the back of the canvas, and I’ll do so accordingly.
So far, everyone considers leaving the back of the canvas as it is the best thing to do. Thanks to all of you. I think my doubt is resolved. Thanks again.


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## Steve Neul (Jul 28, 2020)

I don't understand the use of gesso for an oil painting. It's described as a primer. If you purchase a primed canvas would it be necessary to prime it again with gesso?


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## Arduy (May 31, 2020)

Hello Steve Neul, thank you for posting. Until now I've never prepared a purchased, already primed canvas, but now I do: I don't know how the priming was made, and with what products. I can't know if the canvas and its fibers are well protected and isolated in order to receive oil paint, and now I do it differently altogether, but we are not quite on topic here because the main subject here was priming the back of a canvas. if necessary I could open a new topic to tell you how I do prime my canvases now. Thank you again for your reply.


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## Steve Neul (Jul 28, 2020)

Arduy said:


> Hello Steve Neul, thank you for posting. Until now I've never prepared a purchased, already primed canvas, but now I do: I don't know how the priming was made, and with what products. I can't know if the canvas and its fibers are well protected and isolated in order to receive oil paint, and now I do it differently altogether, but we are not quite on topic here because the main subject here was priming the back of a canvas. if necessary I could open a new topic to tell you how I do prime my canvases now. Thank you again for your reply.


As for as paint goes, I'm more of a house painter and finisher than an artist. I'm still new at art painting. I did know better than prime or paint the back side of a canvas. I'm not concerned about adhesion of the paint. I just see two reason to add more primer to a primed canvas, one is foxing from the cotton fibers and the tannins in the wood frame bleeding through the canvas. Then I would be inclined to use a shellac based primer. I'm trying to get back into art painting again after 11 years and one of the old primed canvases I had has a line running around the parameter of the wood frame where the tannins from the wood are bleeding through. The canvas was stored in a warehouse not climate controlled and I'm sure very damp from humidity. None of the finished paintings I did is showing any marks however 11 years isn't that old when discussing artwork. I sure would rather take the time to re-prime the canvasses to be on the safe side, I just never heard of doing it before joining this forum. That is why I'm here.


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## Hunter1 (Jun 7, 2020)

Hi, I paint plein air mostly, I use preprimed guesso panels. it's all I feel is in the grain of the weave of canvas, even guessoed from the maker. I normaly put at least one coat on a new panel. I experimented using 3 coats and sanding in between coats. Canvas surface was to smooth with no tooth to grab paint the way I like it.Now for painting in my studio I use framed canvas, I do the same one to two coats till I get the tooth on the canvas that I like. In 52 years of painting, I have never guessoed the back of the framed panel. Just my 2 cents.


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## David Stead (Aug 3, 2020)

*This might be useful:*

Try my YouTube channel: David Stead Studio. There's a full demo on stretching a large canvas and tips on materials etc.


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