Canvas Stretching Question

[WilliamPatrickMoore]

I have noticed that people are stretching onto both strecther bars with corners that can be later tightened by driving wedges into them and onto frames with fixed corners (nailed, glued, stapled). Do those of you using fixed corners ever find the canvas becoming loose? Over time? With larger prints? Do those of you using stretcher bars with adjustible corners find a need to tighten them later?

[namartinnz]

I make my own fixed frames, using v nails an a 40mm nail in each corner, with 3mm mdf board glued and nailed to the back. I also edge glue the sides and back on the canvas to the frame. Using Breath Color Chromata canvas, if stretched properly, the canvas hasn't loosened. When I was first using the technique, due to lack of experience I noticed a slight slackening which could be fixed. My very first canvas used as a sample, done about 4 years ago by the man I learned the technique from, is still perfect.

Saying that, a standard canvas I stretched on stretcher bars and stapled from about 5 years has now gone a little loose and could use some driving wedges. Humidity and type of canvas used could have a bearing on how your canvas performs over time.

[WilliamPatrickMoore]

I have noticed that people are stretching onto both strecther bars with corners that can be later tightened by driving wedges into them and onto frames with fixed corners (nailed, glued, stapled). Do those of you using fixed corners ever find the canvas becoming loose? Over time? With larger prints? Do those of you using stretcher bars with adjustible corners find a need to tighten them later?

I am hoping to get imput from everyone stretching canvas about possible problems they have encountered. A concensus opinion about fixed corner frames versus stretcher bars would be great.

[dgberg]

The adjustable cornered frames with wedges are usually a pre cut/pre purchased type of frame. I have never used them as we make all our own frames. Mitred and glued and stapled at the corners. No wedges. Yes they tend to slacken with changes in humidity. I purchased a half gallon of the Tight-n-up,canvas retensioner. Works great,just spray it on the back of the canvas and the canvas shrinks and Tightensup. You can find a whole lot more about it with a google search.

[williamrohr]

A lot depends on the environment where you do the stretching and the type of canvas.  If you use the modern canvases with some synthetic fiber content there seems to be less problem and even less if you have the kind with a double thread in at least one direction. (I think its called a double warp thread).  The biggest factor seems to be humidity.  If you can keep the humidity at 60 - 70 % when stretching the canvas will later shrink and tighten where-ever the customer takes it.  In our case we are in a seaside location where the humidity is rarely below 70% and we have had no problems.  I also use a stretching machine that creates a uniformly tight canvas in both directions which seems to help.  As to the frames, we use wide (2 1/2 inch) hard wood frames which are glued and underpinned.  If we don't use this level of frame the stretching can cause distortion.  Be particularly careful if you hand stretch on pegged stretcher bars because if you do not get a uniform stretch it can pull the frame "out of square" which most people easily perceive and is very hard to correct.      Bill

[ternst]

I've been using stretcher bars for nearly three years now with no wedges and no problems. One key I think is to use a heavier concentrate of the varnish (I use Glamour II with 25% water), which might help eliminate the cracks that Dan Berg and some others have talked about having issues with, and also that you stretch the canvas tight enough. I use the method that Bill Atkinson taught me several years ago, which creates a tighter stretch than you can get with the machines. No sagging or loosening up of the canvas, even on big prints (38 x 72). I also know of guys who use the same Breathing Color material and are constantly having issues with sagging and use the wedges on all corners - too much water in the varnish solution and not a tight enough stretch...

[fdi]

Before my company started manufacturing stretcher frames for a photo lab and selling them to our online customers I did an informal survey of some custom framers I knew. Since most custom framers have mitre saws and v-nailing equipment many do not use stretcher bars. You do have to ensure that you are using a quality canvas and getting a good stretch and as others mentioned you have be careful about the humidity where it is stored.

Cheers, Mark
Frame Destination, Inc.

[OlinYered]

I am one of the users currently cutting 45 degree miters, and using glue and V nails.  I am looking to stretch 'giclee' canvas (eg Epson Canvas), and am considering purchasing a canvas stretching machine for this purpose.

I have been making my own stretcher bar molding starting from stock lumber, trimming in order to obtain a suitable 'lip'.  I would much prefer to purchase molding that has an appropriate canvas 'lip' already, as this is very time consuming (and I lack the pro tools).  I know that such a product exists.  However, based in Canada, I have not found a supplier.  

Q: Does anyone know of a supplier of canvas stretcher molding? For Canada?

I am currently hand-stretching, but the entire process is taking far too long: making molding, hand stretching, etc.  Does anyone have experience in using a V-nailed molding in a canvas stretching machine?  It would seem to be the right way to go with these machines, as opposed to floating stretcher bar corners.

Q: Does the V-nail, mitered corners approach lend itself to machine stretching?

Last, this thinking is based on an underlying assumption that a V-nailed corner on stretcher molding is of appropriate quality for the mid-market giclee market (this is not a museum quality approach) and that the economics of manufacturing the product in this way is much cheaper than the stretcher bar option (as well as being more flexible for customization).

Q: Does the community concur with the assumption?

[Shawn]

I am one of the users currently cutting 45 degree miters, and using glue and V nails.  I am looking to stretch 'giclee' canvas (eg Epson Canvas), and am considering purchasing a canvas stretching machine for this purpose.

I have been making my own stretcher bar molding starting from stock lumber, trimming in order to obtain a suitable 'lip'.  I would much prefer to purchase molding that has an appropriate canvas 'lip' already, as this is very time consuming (and I lack the pro tools).  I know that such a product exists.  However, based in Canada, I have not found a supplier.  

Q: Does anyone know of a supplier of canvas stretcher molding? For Canada?

I am currently hand-stretching, but the entire process is taking far too long: making molding, hand stretching, etc.  Does anyone have experience in using a V-nailed molding in a canvas stretching machine?  It would seem to be the right way to go with these machines, as opposed to floating stretcher bar corners.

Q: Does the V-nail, mitered corners approach lend itself to machine stretching?

Last, this thinking is based on an underlying assumption that a V-nailed corner on stretcher molding is of appropriate quality for the mid-market giclee market (this is not a museum quality approach) and that the economics of manufacturing the product in this way is much cheaper than the stretcher bar option (as well as being more flexible for customization).

Q: Does the community concur with the assumption?

There are many Canadian suppliers for stretcher bars..most frame molding suppliers have stock. Triple Touch, Larsen-Juhl (Toronto based) etc. I have been using them for several years and as of yet have not had problems. I just recently switched to using Breathing Color canvas and Glamour II veneer. So far very pleased with the results.

My stretcher bars are mitered, nailed and glued so far so good. Stretching using a home built stretching machine which, if not pretty , does the job very well. Details of this have been posted on the forum with a website link as well.

Getting a good tight stretch is the key...without overstretching.