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-   -   Help, Saggin Linen! (http://portraitartistforum.com/showthread.php?t=8957)

Lisa Gleim 01-02-2009 06:38 PM

Help! Sagging Linen!
 
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??? :bewildere
Thanks!
Lisa

Michele Rushworth 01-03-2009 12:20 AM

I've had that happen and I've had to restretch it. I keep the corners attached to the stretcher bar so it doesn't get out of alignment and then I remove and re-staple it section by section in the same order as if I was stretching a new canvas. Pull as tightly as you can.

You can avoid the problem somewhat by storing the linen in a warm dry place and by only stretching it on a warm, dry day (not always an easy thing here in Seattle!)

I haven't had much problem with this since I bought some serious($100 !!) molybdenum canvas stretching pliers. It seems that the first time I stretch it is sufficient, most of the time.

I personally wouldn't spray anything on the back of it.

Lisa Gleim 01-03-2009 12:00 PM

Hi Michele,
Thanks! I have re-stretched it three times already!!! uuuuuuuuuuuuuu
It starts of quite nice and tight and then gradually loses that tightness. It is so humid here in Atlanta and I have this problem on occasion but not this bad. I even set it up next to a space heater but no luck.

I have been stretching my own linen for 16 years now and have NEVER come across a problem like this one. If I hadn't already started the commission and gotten so far into it I would start over.

Thanks again!
Lisa

Tom Edgerton 01-03-2009 12:10 PM

Lisa--

Search this site, as there are other threads addressing this problem too.

I've had the same problem, and it's somewhat endemic to where we live. Most of my paintings sag a little when the season changes to winter and the humidity goes down. But if you restretch and over-tighten, when summer comes the canvas almost hums it's so taut. Usually when the paintings live in the same space for a year, they stop changing so drastically. I don't know how much sag you're getting, but use caution due to this seasonal variance.

Bill Whitaker has suggested stapling foamcore to the back of the stretchers, to even out the changes in humidity over time (protects the painting too). Others have sealed the back of the canvas itself with various preparations, but I'm somewhat timid to do so. It may be perfectly fine.

I especially wouldn't use alcohol...except to ply the artist.

Michele Rushworth 01-03-2009 12:21 PM

Maybe it's time to mount it to a panel. In Kevin McPherson's first book he has good step by step instructions on how to do that.

Lisa Gleim 01-03-2009 12:27 PM

Thanks Tom & Michelle! I will search the forum again but I think Michelle is right, I need to just mount it on panel. aaaarrrgghhh!
Lisa

Richard Bingham 01-03-2009 03:02 PM

Was this a canvas you stretched and primed yourself, or was it pre-primed roll canvas which was mounted on stretcher bars?

Correctly done, a "home-made" canvas is usually more stable than those made up from pre-primed roll stock. As Tom notes, seasonal changes in ambient temps and humidity normally affect linen, and adjustments made in "slack" times may be too much. It's actually the major complaint against using linen, which seems most prone to be affected by climate change, and depending on the locality where you live, and where your paintings may be placed, other fabrics may be a better choice. Polyester is incredibly stable and unaffected by changes in the weather. Hemp is also far less reactive than linen.

As Tom notes, Bill Whitaker's suggestion to insulate stretched canvases from behind will not only ameliorate seasonal sagging, but will greatly extend the life of stretched canvases generally.

Perhaps spraying alcohol on the backside of a sagging canvas would re-shrink it, but I think that would only depend on the water content of the alcohol. Rubbing alcohol has a considerable percentage of water in it. Spraying the back with plain water would be a temporary fix, as the canvas is certain to sag once again when that added water has dried. Using an alum solution for the spray can be effective and "permanent" if sagging is minimal. A tablespoon in a pint of water works well. Alum will considerably toughen the glue size.

Mounting to a panel can be problematic: what kind of panel should be used? What kind of adhesive to use? Mounting to a panel may also obviate the main (only?) advantage of painting on a stretched canvas, i.e., the light weight of larger pieces.

Lisa Gleim 01-03-2009 05:15 PM

Hi Richard,
Thanks for that. The linen is pre-primed which I cut and stretched myself, as I have been doing so for the past 16 years. It was nice and tight when I originally stretched it months ago. It sagged a bit and I tightened two sides. Now it is sagging again. The sagging isn't obvious, no ripples or buckles it is just very floppy when I paint on it.
Where can I find Alum?

Julie Deane 01-03-2009 07:35 PM

Lisa,

How big a canvas is it? There are other options, depending on the size.

Lisa Gleim 01-03-2009 10:56 PM

Hey Julie,
It is a 30x40


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