Oil Painting on Canvas
This is one of the most FAQ I have come by over the years.
Oil paint gets increasingly hard and brittle as it ages, so it prefers a rigid, stable support; hardboard, properly prepared, is by far the most permanent and cost effective option. Flexible supports like cotton canvas moves, even when the painting is sitting on a wall; changes in temperature and humidity will cause the canvas to expand and contract. Moreover, oil paint is acidic so if it is allowed to seep thru to the canvas, it will cause it to rot and fall apart.
I still paint oils on canvas when the painting is larger than about 24x36". Wood panels just get too heavy and cumbersome to manage when they are too large. For example, with these two waterfall paintings, the first one is 36x24” on cradled hardboard panel, the other one is 72x36”, on canvas.
Painting in oil on a flexible support is not the most permanent option but there are ways that you can prepare the canvas to achieve the best results possible.
1. Add a coat of Golden’s GAC 400 on the back. This is a fabric stiffener that will minimize the movement of the fabric. Also, the resin coating will prevent absorption of atmospheric moisture as temperatures fluctuate, which normally causes the fabric to flex and relax.
2. Add a coat of Gloss Medium or Golden’s GAC 100 to the front, right over the gesso if it is already pre-primed. This will create a sizing effect so that the oil will not be able to seep thru to the fabric.
3. Add extra layers of gesso on top of the GAC 100. I add about 20% Gloss Medium or GAC 100 to the first layer of gesso to give it more adhesive strength.