Stretching raw linen

[Richard Bingham]

Hi Jean, You "got me" - What's the "credit card trick" ?!? (couldn't seem to find the thread)

Looking back on 500+ years of oil painting, there's little question a properly constructed panel is the best support for an oil painting. Weight becomes a factor in larger works, however, so a stretched canvas becomes the better practical choice. Some folks dislike the "bounce" of stretched canvas, personally, I enjoy that give under the brush.

Because lead/oil grounds have proven to be archivally permanent, and because I prefer the surface, it's my first choice. It isn't necessary to wait six months to a year before painting on a lead/oil prime. Painting can begin as soon as the primer is dry enough to work on, although it definitely improves with age.

Titanium/oil priming? Should be OK, although slow-drying and very different from lead/oil. It could be classed with other oil-prime variants. (oil/whiting, oil/clays, etc.) For painting, lead compounds and linseed oil is a chemical marriage made in heaven. Painters should be aware of the very real benefits these materials provide in terms of permanence, handling and technique.

There's nothing "wrong" with painting directly on a glue-sized canvas. Underpainting then becomes the "primer". The surface is obviously rougher and a bit more absorbent than oil primed, however.

Another possibility that eliminates all fabric preparation is to paint on polyester canvas, which only requires to be stretched, then roughened a bit with sandpaper before painting. Sizing is necessary only to isolate natural fibers from contact with oil. Priming is necessary only to improve the surface of canvas by filling interstices of weave, or providing a reflective or colored ground, or particular characteristics of surface and/or absorbency.

The best research is to run your own tests. Put test samples in extreme conditions of sunlight, heat, damp, cold, outdoors in the weather, etc. Failure modes become quite apparent within a fairly short time. The main objection to an acrylic ground under oil paint is that acrylic resins remain indefinitely flexible. (Theoretically, at least - after 60+ years, so far, so good) Oil paint films on the other hand, inevitably become increasingly brittle with age. It's not sound engineering to have a flexible material underlie a brittle one . . . failure of some sort is inevitable.

That said, acrylic primers are useful and easy to apply, and it will be many decades before such considerationss would become apparent. All of our work should be worthy to survive that long!

My personal bias is the materials and methods of oil painting were perfected 500 years ago. Proof of the soundness of traditional materials and techniques is evident in the great number of masterworks that survive from the 1400's onward. Why "mess" with materials that lack this provenance? If it ain't broke . . . don't fix it!

[Jean Kelly]

Richard, thank you so much for such an informative answer! I did'nt realize that I could paint directly over the RSG and think I will try that next time. I love the color of linen, and a light sanding should take care of the excessive roughness, as well as saving me a lot of work in applying the primer. I understand your point about flexablity and the brittle nature of aging oil paint.

Again, thank you!

Jean

[Jean Kelly]

If I did this right, here is the link to the thread with the "credit card" technique .

http://forum.portraitartist.com/showthread.php?t=5202

Jean

[Richard Bingham]

Jean, thanks for posting that link.

There are some problems with discussion on that particular thread . . . truly, "rolling your own" is harder to do correctly than it appears to be.

[Allan Rahbek]

This is a drawing of a priming knife from around1640. The curved shape prevented the knife from furrowing the priming paste when dragged across the canvas.
Since the canvas will give inn a little when the knife or spatula is pressed against it you will have to use a tool with rounded corners ............ a credit card.