Polyester or linen, what is the most archival surface to paint on?

[Steven Sweeney]

Richard,

Here are some folks talking about adhesive applications, from about 5 years ago . . .

http://forum.portraitartist.com/showthread.php?t=1769

[Richard Bingham]

Thanks much, Steven!

(I realize that similar questions and discussions seem to "recycle" over time . . . that probably becomes boring for those who have already been there, done that and bought the tee-shirt. In this case, it's well to revisit the older threads, because of the reference to Studio Materials. Alas, Mike Ozog threw in the towel on that enterprise a couple of years ago.)

[Allan Rahbek]

Sharon,
20 years ago I got a roll of unprimed polyester fabric that I primed and painted on, The paintings are perfectly straight without any bulging or sagging. I did not like the structure of it because it was like felt and rather course, but it hold the paint nicely. I think that it was primed with Acrylic gesso.

[Richard Bingham]

Originally Posted by Sharon Knettell

. . . Pollack's paintings are falling apart (tant pis ) because they were painted on cotton. . .

Ha ha ha ha. That ain't the only reason, Sharon, but you're right. Cotton canvas and large size both present major problems for the longevity of a support.

It is true that a number of people (gallerists and patrons) are attracted to linen only because it was the material of the "Old Masters".

The climate where you live and work (or at least, where your paintings will end up) has much to do with "permanence". In sunny, dry Spain, El Greco's (and Velasquez' Murillo's, Zurbaran's etc., etc.) canvases remained in fine condition partly because of ambient conditions.

In fact, constructing large painting supports (over 3 feet) presents enough difficulties in terms of "engineering" that it's for all practical purposes as different a problem from making up small supports (up to 30 inches) as building a house does compared to making a packing crate.

[Tom Edgerton]

Richard and Sharon can speak to these issues way more than I, but having scientists in my extended family, I've absorbed a lot about product chemistry over the years.

Generally, the three things that will degrade artwork most over time are water, movement, and materials that are innately too alkaline or acid (not a neutral ph). Polyester eliminates a lot of these problems because, as has been said, it doesn't absorb water into the interior of the fiber, and thus doesn't move as much due to changes in humidity, and it's ph neutral I believe. There are a lot of traditional materials--paints, glues, etc.-- that were never chemically neutral/inert or crafted to be. So I'm not convinced that polyester is bad mojo just because it's man-made.

I worry a little about painting directly on it, because a polyester fiber is smooth-surfaced. A poly/ natural fiber blend might "grab" the paint a little better, but this may be just squeamishness on my part. Richard, would lightly sanding the poly before painting help any?

Also, here in the South, we get a lot of variance in humidity between seasons. I used to key the paintings tauter in the winter, but realized when summer returned, they'd get so tight they almost vibrated on the wall--it was a little scary. I imagine this extreme variance adversely affects the paint film. So I don't do it anymore, but I've noticed that my paintings around town gradually stop slacking off so much when they stay in one environment for a year or two and figure out "where they live."

Bill Whitaker advised that backing the painting with foamcore stapled to the stretchers would lessen the tautness variance, and I've found this to be true.

Sharon, thanks for the generosity in sharing your research.

[Linda Brandon]

Originally Posted by Tom Edgerton

Bill Whitaker advised that backing the painting with foamcore stapled to the stretchers would lessen the tautness variance, and I've found this to be true.

Tom, can you post a photo of how you do this?

[Tom Edgerton]

Will do ASAP

[Richard Bingham]

[QUOTE=Tom Edgerton]
Here's a thought re/ the conservation paper Sharon presented. The paper speaks in engineering terms of fabric strength, resilience, and the loss of strength in natural fibers over time. It would be well to remember that although linen loses strength ("only 25% of its original strength within 25 years") it approximates the strength of synthetics when new, i.e., plenty strong to take the wind-load of a ship under sail, or made into bags, clothing, etc., etc., the remaining 25% of strength is more than adequate for what's required of a painting on stretcher bars! It's the reason why canvases scores of years old still exist. QUOTE]


Richard,
Could you please give us the source of your quote? does it give the relative strength relationships vis-a-vis other materials?

I found this on JClass sail site, http://www.quantumsails.com/products...ils.asp?CID=13
The mainsails and spinnakers are nylon and the the jibs are kevlar among other state of the art materials.

[Richard Bingham]

No worries, Sharon! (it wasn't that great anyway!) Tom quoted (I believe) the whole reply.

Tom, I think I'm "losing it". The paper I referred to was the paper accredited to a conservation site via the internet, I thought it was in this thread, but apparently it's not. Sharon? By the way, IMO, the paper is very informative, and the information well worth considering in terms of our needs for painting supports.

By invoking the stresses of a ship under sail, I was thinking of times long past, not the present day. I believe most craft under sail have been spreading sheets of synthetic fabrics of one or another type since WWII.

[Alex Sunder]

Theres a company that produces a 50% cottom, 50% poliester fabric. I just ordered 5 meters to test. The price is incredibly cheap. I will let you know what is like.

Alex