Help, Saggin Linen!

Virgil Elliott · 01-30-2009, 10:46 PM

Quote:

Originally Posted by Lisa Gleim

I have a LINEN canvas that keeps sagging. I have tried many tricks, re-stretching for one, lightly misted the back with water and let dry and used stretcher keys.
Does any one have a suggestion on how to tighten stretched LINEN that sags? I have heard that misting the back with rubbing alcohol works. Does any one know anything about that or if it works???

Thanks!
Lisa

Lisa,

Alcohol on an oil painting is definitely a bad idea! There is a product called Tight'n'Up that works very well for tightening slack canvases.

Gluing the canvas to a rigid panel is probably the best thing, if you do it right.

Virgil Elliott

Terri Thickstun · 02-19-2010, 01:58 AM

Hi Lisa,
I just happened on this thread and realize that my response is coming about a year late.
I had the same unfortunate experience a few months ago when I noticed that the canvas on a commissioned portrait was sagging. I was to deliver the painting two days later. Mine was painted on a pre- stretched canvas, 20 x 24. I found a lot of great input but none that worked for my timeframe, so in a panic I decided to try the quickest fix that I found. I have to tell you that I was terrified at the thought of doing this and I'm sure that it is not the best or safest method...but it honestly worked and the canvas remained tight. The instruction that I found online said to heat a pan of water to boiling, pour it into a bowl and using a clean, natural sponge, quickly and 'lightly' wet the back of the canvas...and immediately dry it with a blow dryer. It was an instant fix...not one that I'm proud of, but will probably do again as panic seems to frequent my studio :-)

Tom Edgerton · 02-19-2010, 11:22 AM

I'd be really terrified to use water that hot. Oil paint is remarkably resilient, but anything has its limits. I'm not sure I understand the logic of using hot water. Maybe it affects the fabric sizing or something.

In a pinch, I've misted water onto the back from a plastic bottle/ plant sprayer. Room temperature. Also, I've let it air dry after, with a good result. Some folks would object to water at all, and they may be right, I don't soak the canvas down under any circumstance.

If the canvas was reasonably tight, again, time will lessen the expansion/contraction, but I understand that kind of pressure in a commission situation. Also, not moving it from place to place helps, once it's hung...I've had them slacken from the framer's to my studio in certain seasons. Once it figures out where it's to live, the painting will settle down.

Terri Thickstun · 02-19-2010, 02:09 PM

I absolutely agree Tom, this was a risky process, not one to use if there are other time tested options available. I should note that I paint fairly thin as well and I'm not sure of the effect this might have if one were to have heavy paint on the surface.
Drawing on my vast knowledge of laundry :-), I do understand that hot water and a hot dryer are more likely to shrink most natural fabrics. The temperature of the water did seem to be key and I can't agree more that this shouldn't be a process in which the back of the canvas is overly wet, it should just be a light touch with a damp sponge to dampen the canvas.

Tom Edgerton · 02-19-2010, 02:18 PM

No harm, no foul, as they say...

Richard Bingham · 02-21-2010, 07:20 PM

Young oil paint is amazingly resilient and tough. Old paint films which have become embrittled are likely to crack and fall off the support when subjected to radical stresses.

Painting on stretched canvas is a relatively "chancey" proposition over the long haul, because the support is inherently flexible, and ultimately, the paint will not be. To avoid grief over sagging, slack, or puckering canvases, the best "fix" is for the painter to be knowledgeable on the properties of painting supports - it's hard to beat painting on your own supports if you have the skill and the time to make them.

In short, the most commonly used materials are quite given to "slacking off". Cotton canvas is not particularly strong, and will often become slack simply from the attack of being painted on. This is less of a problem for a glue-sized/oil primed canvas than for one primed with acrylic gesso which does not effectively shrink the fabric, and remains flexible.

Linen is a stronger fiber, but subject to changes in ambient humidity; slacking off in damp weather and tightening up in dry weather.

Hemp is much stronger than linen, does not get loose when worked on, as cotton does, and is much more resistant to changes in humidty, but it is not commonly offered pre-primed or pre-stretched.

Polyester is eminently stable, stronger than natural fibers, unaffected by humidity, and can be painted on directly without sizing or priming, but there is no "old world mystique" to using it.

Mary Cupp · 02-21-2010, 09:33 PM

I have never seen hemp canvas but it sounds quite interesting. I know the hemp fiber is exceptionally strong. Has anyone had any experience with it?

I use mostly cotton canvas but it is a compromise, as linen is so expensive. I am wondering if hemp would be an improvement without as much expense. Does anyone have any advice on using it?