Brands of Stretcher Bar

[Paul2660]

What brands of Stretcher bars are people using?  and are you getting them pre-cut or buying them in foot length?  

I am having trouble with the Omega brand bar I have been using in that it seems to be too harsh on the edge, causing slight openings when stretched.  It has a seemingly nice rounded edge, but still seems to want to pull.  I realize it also might be the force being used during the stretch.  The Omega has a 1 3/4"inch shoulder.

Thanks
Paul C

[framah]

What do you mean by slight openings?

[Paul2660]

On the curve where there would be the most pressure, I will get areas where the canvas has pulled, leaving a slight gap, which will show in pure white.  

I am not sure if this is the bar with a too harsh edge, too much pull during the stretch, or combination of both.

If the canvas is coated prior to the stretch, which I do, then you can't go back with standard dye's to fix these spots as the coating will prevent a good mating.  

Paul C

[framah]

I understand now... the ink is breaking up and the canvas is showing thru the image. Right?

If that is so, then, yes you are probably pulling too hard.  Prints on canvas are more delicate than paints on canvas when it comes to stretching.

This is an ongoing problem with prints on canvas. Too tight and it cracks or flakes the image and too loose and the canvas is floppy on the frame.  

Alot of framers are solving the problem by dry mounting the canvas onto foam core or some sort of board.
This eliminates the problems noted above but removes the possibility of having a gallery wrap where the image extends down the sides of the frame.

I always sand the edges of the stretcher frame to make sure there are no sharp edges.

I just got done printing 4 images onto canvas and then gallery wrapping them and while I got it ok, I still had tiny spots where the canvas was folded back into itself at the corners that lost the ink. All you can do there is to find a marker close to the color in the area and touch it up.


This is why I prefer to frame them!

[ternst]

Paul:

You are getting this with BC canvas, and after the varnish? I've done hundreds of them - with 300-350 pounds of stretch pressure - and never had anything like that happen. I know another photographer who just opened a gallery with nothing but his canvas prints - 180 of them - and almost all are, well, I probably should not give an opinion on their quality. Anyway, all of his cracked pretty bad all along the edges when stretched, so he glued strips of wood veneer all around each frame to hide the cracks - looks really sick that way, especially when you know why he had to do it. He was using the Epson canvas and spraying with Krylon out of a can! You should not be having those issues with the BC canvas. Their customer service may be horrible but their canvas has always been great to me...

Tim Ernst in Arkansas

[Dward]

Alot of framers are solving the problem by dry mounting the canvas onto foam core or some sort of board.
This eliminates the problems noted above but removes the possibility of having a gallery wrap where the image extends down the sides of the frame.


One way to mount and still do gallery wraps is to glue masonite (or formica, or some other thin, stable substrate) to the face of a gallery wrap stretcher, trim with a router, then glue the canvas onto the masonite with a suitable adhesive (I use Mighty Muck).  When the glue has dried, wrap the canvas around the edges of the stretcher and staple as usual.  Less flaking at the corners because less stretching force is needed, and the canvas-on-panel method makes a more durable, damage-resistant final product.  The major disadvantage is the added weight.

David V. Ward, Ph. D.
www.dvward.com
David V. Ward Fine Art Photography

[Paul2660]

Hi Tim,

There were not with BC, I was using up some older Canvas, mainly Epson, but some Sunset also.  It doesn't happen all the time, but it did ruin one tryptic I had worked up and I had to reprint it.

I also just switched to Glamour II from the Clearstar so hoping it will get better.  

I currently don't do the stretching, and I think the company I use is not being as careful as they could be.  It's something I need to learn to do as I prefer the gallery wrap look.

The issue is better described by Framah.  The canvas is separating right at the curve.  

Just got the BC glossy canvas and it is beautiful.  

Thanks
Paul

[framah]

Ok... here's my dumb question... Who is BC?  

Also... 300 to 350 lbs of stretch pressure?? I find that pretty much impossible to believe. If doing it by hand there is no way you could achieve that and if by machine, I find it hard to believe it would pull that hard or even have a setting that high.

My underpinner drives vnails into hard wood with only 80 lbs of pressure so why in the world would anyone want to  pull on canvas with 350 lbs of tension? Plus you can warp a stretcher frame even doing it by hand so imagine what that much pressure would do to a frame.

Maybe 30 to 35 lbs but not 300 to 350. Sorry I don't believe it.

[framah]

Another thought... you can substitute gatorboard or even foamcore for the masonite   and make the package alot lighter.

[Paul2660]

sorry,

Breathing color = BC

I am also wondering if some of the problem is because I am using a glossy canvas i.e. coated canvas instead of a traditional matte canvas.  The glossy canvas may have a more sensitive surface.  
 
I am using the Epson 9889, and PK inks.  Didn't want to switch to matte inks on this printer since I still mainly print on RC paper.  

Thanks for the idea of the gaterboard.  I have seen other posts on mounting the canvas to a board and going that way, but like you mentioned, you lose the gallery wrap look, which to me is one of the best things of Canvas.  

Paul C

[Paul2660]

David,

Nice idea, on the masonite.    I can see where that would take pressure off the edges since you are only needing to pull them down for the stapling.  

Paul C

[ternst]

framah:

Sorry you don't believe - I really could care less, although I have to admit it does sound rather high. I actually never measured it myself but the guy who taught me the method that I use gave me that figure - he is a scientist/perfectionist and I tend to believe him (and he has the tools to measure such things with). Do it by hand - oh goodness, I would never do that, nor ever have. This guy's method is not a machine really, but is super simple, cheap, and does not involve canvas pliers, thank goodness - takes about ten-fifteen minutes per frame from start to finish (this is his design and I'm not at liberty to share). The BC canvas holds up well to this pressure, the prints are indeed "drum tight," perfectly even all the way across, and don't ever sag (I've stretched prints up to eight-feet long with no worries). Warp the frame? Not if you use proper braces - never had one warp.

[framah]

OK... think of it this way. When you torque the bolts  on the head on an engine, you torque them to
65 to 75 ft/lbs. If a bolt is torqued too much you stand the chance of warping the metal or even stripping the threads.

Do you really believe that fabric can withstand 350 lbs of tension without ripping apart?

Please, ask him again about this and how he came to that number and report back to us. I would like to know how he came to that figure. Like I said 30-35 maybe.

Oh, and framers have been stretching canvas by hand...meaning with canvas pliers and an air powered stapler... for a long time and is the standard in the industry for stretching canvas.

There are various mechanical stretching machines on the market but if your friend has a way to make our job easier and quicker, tell him to get it out there and people will pay him for it.

I know you could care less but when you use stats that don't make sense without any proof to back it up, it lessens your credibility to offer helpful advice.

[ternst]

Hey framah, I'm satisfied with his numbers - the canvas I use is very strong - I'm happy with my results, and will leave it at that. My credibility isn't an issue here (I'm not trying to sell anything or give advice, only used my experience as a reference to the issue that Paul was having). Yup, I know folks have been using canvas pliers for a long time - the standard of the industry, just like film...