Sunday, May 22, 2011

18th century French gastroenterologist's dredge, from the Louvre.

Here I am in Old Lyme Connecticut.I taught a workshop today and will again tomorrow. I think I will write just a little more about canvas as the comments have been filled with various ideas, some good and some confused about that. Bullets please.
  • You CAN put an oil ground down over acrylic preprimed canvas. Let it dry for a good long time before using it. At least several weeks.
  • Gesso is made with rabbitskin glue and whiting, marble dust etc. The acrylic stuff in the jar from the art supply store is not gesso, They just call it that. I hate the stuff. It might or might not be a good ground for oil paint, but it is unpleasant to work on. Your paint will stand up on the surface better on an oil ground.
  • I often use TEMPERED Masonite as a panel. The untempered would be preferable but it has become hard to find. I use oil primer on it, I would not use acrylic primer over this though.
  • I use Zinsser oil timer. They are better known for shellac based products. You can certainly paint on shellac, but I think a primer is better, it has substance, tooth, and small degree of thirstiness that I think is good.
  • Shellac is made from Lac beetles, it is not a plant exudate or a varnish from a tree. It doesn't keep terribly well. It thins with alcohol and dries extremely quickly. You can shellac watercolor paper and paint in oil on it.
  • Here is a tutorial from the blog on making panels
  • If you can afford it, use Claessens type 12, mounted on panels that is the best fix I think, but it is expensive. Sourcetek has those. I can't afford them. I use acres of canvas.
  • I find the surface of the Polyester canvas to be too hard. It is a little like painting on a window screen. But I want to experiment with it some more. Synthetic is the future, it is stable and never rots.
  • Fredrix makes a very high quality oil primed cotton with an oil priming, called Scarlet O'Hara, you can get it here.Link
  • Here is a link to Jerry's for the Centurion oil primed linen made by the Chi-Coms.
  • Here is a link for cheap panels with oil primed linen on them. They are not the quality of Sourcetek, but the surface is nice.
  • Here is the same Chi-Com oil primed linen prestreched, sold in boxes.
  • Here is a link to Jerry's for Claessens type 12 a premium oil primed linen. It is expensive but a wonderful product.
  • I think cotton is as good, or nearly as good as linen, but it must not be the thin stuff that is sold at the mall craft supply stores. A 7 oz canvas is too light. 12 oz is about right. Notice the surface. I don't like a rough weave, but you might.I often use portrait linen that has a fine weave.


David Teter said...

Yeah my memory (damn thing) of that article on masonite/hardboard panels was a bit off so I found it, originally printed in American Artist Magazine and referenced by another reader in your blog tutorial post on making panels. Link here so I don't spread misinformation.

You're right, my confusion with shellac was that they scrape from trees, the resin from beetles. Either way I don't paint directly on the shellac but use it as a primer to seal the surface, then use gesso for a toothy surface as you said, and use oil primer too sometimes but they keep reformulating it so you don't always know what you are going to get.

My concern has been primarily archival so I hope the use of zinsser shellac based primer is safe. Shellac has been around for thousands of years, is used as a binder in india ink, and is a stain blocker or barrier coat against possible contaminants in hardboard and compatible with most other finishes all according to Wikipedia.

Simone said...

I want to reuse linen panels with failed or unfinished paintings on them. What suggestions for preparation do you have for that?

Lucy said...

That Zinsser stuff is strong. I got real sick from it when it was used to prime a stairwell in my home.
Be careful, everyone and VENTILATE.

Thomas Kitts said...


Thank you for going into painting grounds in such detail. I'd like offer a little clarification to a few of your main points, however.

1. Yes, do not use any housepaint primer. It is not formulated for fine art application and will crack and yellow in just a few years.Good on a house. Not so good on a painting support.

2. It is a perfectly sound painting practice these days to use tempered masonite. The amount of oil used in is now less than a teaspoon per 4 x 8 foot sheet. Far less than was used in the past by an order of magnitude. Applying acrylic gesso (Properly known as 'acrylic dispersion ground) is okay on tempered masonite so long as the surface is has been lightly sanded, then wiped with a little isopropyl alcohol to remove any excess oil which may have bloomed to the surface after manufacturing. (Unlikely, but it can happen.) In the end, i is the mechanical bond between the masonite and acrylic dispersion ground that holds, not a chemical connection.

3. If an artist plans to apply a traditional oil ground then a size is required. If he or she is applying an alkyd ground, such as Gamblin's alkyd ground, then it is not a concern as the linoleic acids in the alkyd resin have been neutralized and do not attack the substrate.

4. If cotton is glued to a rigid support then it is equal in durability to most linen, all other concerns being equal. But if it is stretched is is less durable, again, if all other concerns are the same. Linen wins with regards to longevity due to its strength and the way it matches the expansion and contraction coefficient to a mature oil film.

However, having said that, any rigid support beats any stretched one, so this should be kept in mind if longevity is the desire. Panels live longer.

I hope you understand I am not challenging your points, just adding to them. If anyone is interested in accessing more of the conservation science of painting I recommend visiting, a free online resource for painters of all mediums. Of all levels. A visitor can be assured the answers received will reflect sound painting practices as they are currently known. With respect.

And yes, for the purpose of full and complete disclosure, I am one of AMIEN's Moderators who answers these kinds of questions, and offers explanations if they are called for. I don't recommend AMIEN because I get something from it (Quite the opposite, actually) but because it can be very hard to know where to go to get solid advice. Assuming a painter cares...

As always, you post a great read, and important things for painters to think about.

Thank you,

Thomas Jefferson Kitts

Stapleton Kearns said...

I think Shellac is fine. But it doesn't provide any absorbancy. You may not need that, or you might. I do.

Stapleton Kearns said...

I seldom think it is worth the trouble unless the paint on them is very thin. I think. Make new.I have decided that if I would need to sand them for more than 30 seconds they are gone.

Stapleton Kearns said...

I always prime panels outside. I like drying them on the sun and there is the whole yard in which to lay them out.

Stapleton Kearns said...

Thanks for the info, I have posted a link and a little about Amiens.

David Teter said...

Stape and Thomas,
Thank you, very helpful. I prefer easy and archival safe. If I can eliminate the extra step of shellac primer it's just as well.I usually just want to paint.
The AMIEN link will be helpful.
I wonder how long it would have taken to get this info pre-internet.

Anonymous said...

Hello Staple,

I came across your wonderful blog and have a question about shellac. I am working on a mixed media work on Arches cold press 300 lb paper and would like to use amber shellac as a wash over a portion of the work. I have tested it and love the way is looks but am a little concerned about permanence. The work will be museum mounted in a shadow box with UV plexi and not exposed to direct sunlight. Any thoughts you can share about potential pitfalls with shellac would be greatly appreciated.

Kind regards,