Minh,
For the ultimate in permanence, I would paint on Sunbrella nylon canvas attached to a honeycomb aluminum panel with a conservation adhesive. These panels are quite expensive, but you said forever. I would probably use an alkyd ground, most likely Winsor & Newton's Oil and Alkyd Painting Primer, or W & N's Foundation White (white lead in linseed oil) after sizing with Gamblin's PVA Size. I would let the ground cure for at least six months before I painted on it. I would wipe it with a cotton cloth slightly moistened with odorless mineral spirits to clean the surface, then allow a day for the OMS to evaporate completely. I would then wipe it again with a soft cotton cloth slightly moistened with water, and let that evaporate for a day.
What I would do next would depend on which way I decided to paint it. I can paint many different ways, and I choose the one I feel best suits the concept I have in mind for the picture at hand. I can underpaint in grisaille or in color, or dispense with underpainting altogether and paint more or less alla prima. The basis of any underpainting would be Winsor & Newton's Foundation White, tinted with colors of high tinting strength and/or at least somewhat lean colors. My medium would most likely be linseed oil, used very sparingly, and perhaps walnut oil in the last stage of a multilayer technique for the lighter or bluer areas, such as the sky. I would not use retouch varnish between layers. Instead, I would simply scrub a tiny bit of linseed or walnut oil onto the area to be painted into, and then wipe off all but the faintest trace with a soft cloth before painting into it. For a final varnish I would use Gamblin's Gamvar, after the last brushstroke had had one year to cure. I would clean the surface as mentioned previously before applying the varnish.
The aluminum panels with Sunbrella Nylon I mentioned are available from MuseuM Services Corporation,
www.museumservicescorporation.com
They are expensive. A less expensive alternative would be to mount the canvas of your choice on a wood panel. I sometimes use John Annesley Artist Panels for this. John is at:
www.johnannesley.com/Annesley.html
Mounted on a rigid panel, the choice of fabric is less critical than when stretched on stretcher bars.
I do encourage you to buy my book when it gets published. It will answer many of your questions.
Virgil Elliott
Linear Mode
