Canvas Painting without Stretcher



Hi All

Someone walked in today with a painting on canvas that was masking taped to a matboard. Is there another way to mount canvas rather than a stretcher frame? I'm not sure if you should stretch a painting after it has been painted. Wouldn't that do damage? Anybody out there know? The owner is looking at a frame only scenario.
Many thanks!
Are there margins around the painted area? How
thickly painted is it? It may be possible to attach more material around its edges to serve
as tacking margins, but more information is needed
before that could be discussed.

About 1-1/4" white space around the painting. There are palm trees that have embedded 'bark' that is raised up. Otherwise it looks to be oil or acrylic.

Anna, I sell my art work both stretched and unstretched. I also offer a stretching service. In 4 years of stretching art work, I have never had a problem or caused damage to the piece.

If you don't stretch it tight resulting in a loose canvas, spray the back with water and gently rub it in with hand. It will tighten when the water dries and will not cause damage to art.
I had an oil in the other day. I had stretched it and was nice and tightI let thewater dry and the following day was quite wavy. I restretched it again and same thing happened. What am I doing wrong?
Try stretching it dry. Since the fibers in fabric
are helical, in some circumstances the fabric seems to shrink when wet, as the fibers swell and
tighten the helix. It gets complicated and somewhat confusing.

Without seeing it it would be difficult to say, but the "imbedded bark" comment indicates it probably is an acrylic since acrylic has much better adhesive properties than oil.

1 1/4" white space is plenty for stretching and, if the painting substrate is in reasonably good shape there should be no damage in stretching it. When paintings are ordered through various supply houses they normally are shipped rolled and unstretched.

I'll also harp on another pet peeve of mine since I have the opportunity...

Whenever we, as framers, frame any painting...oil, acrylic, pastel, watercolour, oil pastel,...whatever the medium, it IS our responsibility to our customer and to the artist to make sure the customer is aware of the framing options available to properly preserve the artwork. Many, even on this forum, take the attitude that we only frame the work and are not responsible to educate the customer about proper varnishing techniques, etc.

I say if this is your attitude, then you are not a professional framer...maybe a carpenter capable of slapping four pieces of wood around a rectangle, but not a professional picture framer.

We are the first line of defense against improper preservation techniques and the one consumers trust with original artwork. If we don't continually educate ourselves and pass this information on to our customers, we are doing such a dis-service to our clients that, I believe, a court of law would hold us accountable.

Sorry to use such strong language to push my point, but I find it so obvious and am aghast at remarks made on this forum about the "not my responsibility" approach.

We, as a group, need to be more knowledgeable about how the work we frame is created. What materials are used and why. Our customers expect us to know this information and our claim to professionalism demands it.

I tip my hat to Anna for asking questions like this and caring about the artwork that her clients have entrusted to her.

Not knowing is not a sin...not caring is...

Alright, I'll get off my soapbox...

Dave Makielski
Originally posted by Dave:
...I say if this is your attitude, then you are not a professional framer...Sorry to use such strong language to push my point, but I find it so obvious and am aghast at remarks made on this forum about the "not my responsibility" approach...I tip my hat to Anna for asking questions like this and caring about the artwork that her clients have entrusted to her...Not knowing is not a sin...not caring is...
Gosh, Dave, at first I thought you were admonishing Anna for not knowing what to do, but it turns out you're complimenting her concern.

I agree.

I also agree that mounting to proper stretcher bars -- tapered and with keying provisions -- is the right choice. Handle carefully, and do not flex the painted area of the canvas any more than necessary.

Perhaps it seems cowardly of me, but I would not wet the back of a canvas. As I recall, especially for old paintings on canvas prepared by the artist, there may be a moisture sensitive ground or other elements beneath the paint layer that could be affected by wetting. For me, dry stretching has always provided enough tension for a canvas in good condition.

Note that the cracking is always a possibility for heavily-layered oil or acrylic paints, and a probability for canvas giclees.

Suggestion: Line the frame's lip with something to prevent the paint from sticking to it, such as Volara tape, rag board slivers, or some other padding material. Other methods include fitting with mending plates to provide a slight gap (debris catcher), or attaching strips of alphacellulose 4-ply board to the sides all around (where the staples are), which are slightly deeper then the stretched assembly. That also separates the stretched canvas's sides from the frame's unfinished wood rabbet.
Another thought:

I believe the best and most current information on canvas stretching & framing is from CCI; Canadian Conservation Institute. You can order their "CCI Notes" on this and a number of other framing topics.

Using a solid backer, such as 4-ply alphacellulose or fluted polypropylene board, to insulate and protect the back from mechanical damage is among the recommended procedures.
If someone else has more information than me, please correct what I have to say.

Traditionally canvases were prepared with gesso made from whitting and rabbit skin glue. Spraying any water based product would soften this base. In todays plastic based chemistry (acrylics, polymers, etc) a mild spraying water will have minimal effect on the bases (primer) mechanical adhesion to the fabric.
Good topic Dave. Seems a bit out of place here. Just like this post.

Carry on.
Wow, good info on proper stretching techniques!

I don't know where this "dampening the back of the canvas" while stretching idea came from other than the concept working for making tight is probably not a very good idea though. If it actually worked as intended you'd have to be pretty good to know how much dampening with what weight and canvas material used or you could end up with a ripped canvas.

It is not too difficult to stretch a canvas dry using canvas stretching pliers, a staplegun (or tacks) and folowing the "start in the middle and work your way out" technique.

I think most of us realize this, but it would be good to point out that the stretcher keys are not meant to be used in the initial stretching of a canvas. They are intended as a tightening measure some time down the line after the canvas loosens as a natural process. Keying the stretchers allows for tightening the canvas without having to restretch. A sagging canvas does not provide a proper support for the paint and could ruin a painting or at best, lead to a costly restoration job.

Does anyone know of a reasonably priced tool or a technique that could be used to take length strainer bars and produce a keyable corner?

Dave Makielski
Since most have coverd the basics!~ I will only touch on one area that everyone but "preservator" may have over looked!~ I would like his comments on this!~ I have never seen it mentioned or written any where!~ We take great care to see to it that the canvas is properly framed; the right tighness, varnished when and if needed, the seperation method to contact with the painted surface and the frame, artists have even been up grading to acid free canvas, also to line the wooden frame with tape or some type of neutral barrier!~

But what about the contact to the wooden stretchers? No one ever seems to address this!~ Am I the only one that sees this?~ Should you not at least gesso the stretcher surface that comes in contact with the back of the canvas?~ Are the wooden stretchers magically not acidic?~
I have for years taken stretchers and either gave them a coat of gesso (let dry for at least a week)or sprayed with Krylon Krystal Clear (again let dry for at least a week) the last maynot be air tight but better than raw wood don't you think?

Am I off track here?
Dave, this "dampening the back of the canvas" can actually be found in More Answers for the Framer penned by none other than Paul Frederick. It's #127, page 22. He mentions that you may remedy a bulge on a recently painted canvas by slightly dampening the area on the back.

From this, we probably can extrapolate that some figured if a little water worked, more would work better, and work on old as well as new. He goes even further to say you can apply a little heat if the water doesn't do it. Oh, Lord. If we do more water than recommended, what about that heat thing??

This book was copyrighted by Decor (Commerce Publishing) in '81 and '87.
Gumby, I think sealing the bars has been addressed somewhere. Current standards call for sealing the bars with multiple coats of polyurethane. First prep them by sanding them and rounding off any sharp edges or corners. I'll sand a little between coats and once it's all done and dry I'll sand once more to smooth everything out.

Frame sealing tapes works very well too, and it's fast and easy.

As much as I respect Paul Fredrick, I still don't feel comfortable wetting the back. As was pointed out, the book is close to 25 years old. A lot of things have changed since then.
No James, your not. Gessoing will help dramatically, but the entire stretcher should be gessoed. You also can use a paint such as Kils, but it needs to be thoroughly dry before contact with the canvas.

The canvas itself will act as a barrier...probably until the artist kicks the bucket, but unless restoration is done (relining) the painting is doomed to absorb the leached lignins.

Now, if I sound like I know what I'm talking about it is only because I just spoke last week to a local conservator about this issue. I frame for an artist who sells worldwide and backs his oils with a high grade wood panel between the stretcher frame and linen canvas. He uses nothing but the best quality materials (W/N Artist Grade, Old Holland, etc. and linen canvas.)

Usually he, or his son, stretches his own work and brings it into me ready to be framed. I asked him about the wood panels and sealing them. He said he never thought about that.

There are a number of his paintings scattered all over the world that he plans on one-by-one rectifying this dilema. His work goes for 5-6 figures and certain pieces continue to escalate.

I wish I had addressed the issue with him several years ago, but I neglected to practise what I preach and confer with him on how these panels were sealed. He's quite knowledgeable in many areas, but until we discussed the lignins in papers he wasn't aware of the the leaching lignin problem.

Hm-mm...maybe that's what I'll be for Halloween...

A "Leaching Lignin"!

Dave Makielski
I have used moisture on the back of a canvas to relax it enough to remove a dent, but very little moisture goes a long way. Slightly dampen the area and let it dry. If needed, repeat the process. Never put enough moisture to penetrate deep into the canvas and...

never do this to customers work...

I've only used this on unpainted stretched canvases.

I don't know how this process could be extrapolated to being included in the stretching process...

I guess logically it should work...think of a canvas boat cover. When it's wet and soggy it droops...on a sunny day it tightens after it dries. (Good reason to soak them before putting those darn things on!)

However...a canvas boat cover doesn't have artwork on the reverse side. Just the fact that you are relaxing the canvas with moisture and dimensionally altering it is bad news for the artwork.

Dave Makielski
Framers are to be congratulated for taking the
time and effort to seal the wood of the stretcher
bars, since wood next to cotton or linen is not
a good idea. When that has been done and a backing board, such as a sheet of Cor-X or Coroplast is screwed to the back of the stretcher bars, the back of the canvas will be protected from punctures and pollution. A well-sealed rabbet will help the canvas from aging, too. Moisture on the back of the canvas could be a threat to the hide glue layer, under the gesso, in older canvases, but acrylic gesso should not be affected by a bit of moisture. Anything that is under tension or was dried under tension can be affected by moisture in unpredicitable ways and if a highvalue canvas comes in, with distortions in it, a conservator should be consulted. Jim's suggestions for keeping the paint from the lip of the frame are spot on.

We offer "preservation canvas stretching", which includes complete covering of the stretchers and frame rabbet with Lineco's blue paper/foil rabbet lining tape. IMHO, the absolute barrier of foil is better than a painted coating.

It's optional because it costs more for materials and labor, and some people -- especially the artists themselves -- simply will not pay for it. They fail to understand the value of sealing the bare wood. They think the "traditional" use of bare wood has worked for all these centuries; "It was good enough for _________(insert famous artist's name here), so it's good enough for me".
While on the subject - what about ironing a wrinkle out of canvas from the backside - I have tried it on a friends with their permission & it worked great.

When an acrylic is folded for a while - is there any other options??
Thanks Preservator,FramerDave,Dave thought I was the only one who did this!~
The lets do it cheap do not like the extra charge but The Artists that actually make a living at it and understand they maybe leaving something that will be here for centuries if done well!~ Better than a head stone in some forgotten cemetery!~ To have a painting still hanging on someones wall 200 years from now!~ We need to build the boat that will get it there not just a cheap raft!~ Now that my friends is what you call SUCCESS!~
When that has been done and a backing board, such as a sheet of Cor-X or Coroplast is screwed to the back of the stretcher bars, the back of the canvas will be protected from punctures and pollution.
Whatever happened to the idea that a painting on canvas shouldn't be backed so that the painting can continue to 'breathe'. Obviously this is not the case anymore... so my question is, does the coroplast go up against the canvas or on the other side of the stretchers? Sorry if this is a silly question.
Put the Cor-X on the back side of the canvas stretchers...opposite the canvas side. Its sole purpose is to help prevent punctures, etc. from the back side of the canvas, however sealing the back could also keep cotton loving insects from building nests to a minimum too.

I usually, depending on the frame package design, cut the Cor-X about a quarter inch smaller than the O.D. of the stretcher bars. I'll tack the board spacing the tacks 3-5" apart all the way around except the bottom two corners. I then cover with a dustcover. The untacked corners receive bumpons and I drill a small hole with a Dremel through the bumpons and put a brad through to hold both the Cor-X and the bumpons to the stretcher.

This procedure presumes the stretched canvas is slightly higher than the back of the frame.

Not a silly question...silly.

If anyone sees a problem with this procedure or can suggest an improvement, I'm always open to learning something new.

I remember growing up that the rule always was to not seal the back of the canvas to "let it breath"...somewhere, if you serach this forum you'll find a discussion which occurred several months ago concerning the falacy of this former principal.

Dave Makielski
I'm hearing many people using the cor-x or coroplast for sealing the back of a stretched canvas.

I had been looking for a flatter material(esp. for when the stretcher bars extent beyond the frame), and found "Tyvek". The stuff they wrap houses in. United sells it without the word Tyvek all over it. They claimed it is puncture proof & acid free(or neutral).

The back of the canvas gets Tyvek & then the blue paper over it all for finish. Is any one else loving Tyvek like I am?