Alkyd primer

[M Winther]

"Alkyd primer"

I have sized hardboard (fiberboard) panels with white alkyd primer
(Beckers Nondrop) bought at the hardware store. The result is a perfect
surface for oil painting. The traditional way is to size with rabbit
skin glue or fish glue and then add a layer of oil gesso. Alternatively
one can use acrylic gesso. However, since both glue and acrylic gesso
are water based, the panels will inevitably become warped. This doesn't
happen when using alkyd primer.

Moreover, alkyd primer can be used on any material because it is a
super-adhesive. Nor does it cause rotting in the underlying fabric, so
one doesn't need an underlying layer of rabbit skin glue. It can be used
on any kind of weave, too. It can even be used on a plastic surface, at
least if you sandpaper it slightly. So oil painters can now paint on
virtually anything (plaster, wood, concrete--anything!), just like
acrylic painters. Beckers Nondrop is thixotropic and has a buttery
consistency. Thus, it should be suitable for oil painting, too. Alkyd
primer is less flexible than acrylics but more flexible than traditional
oil primer. It is very strong and non-absorbent.

So forget about acrylic gesso as well as traditional gesso. The problem
is that acrylic gesso does not form a chemical bond with the oil paint.
This means that alkyd primer is decidedly more archival, because oil
paint forms a chemical bond with alkyd. In order to add "tooth" to the
alkyd, so that it becomes a gesso proper, you could add calcium
bentonite, or any other traditional additive. A good idea is to add a
layer of alkyd primer to the ready-made panels that you buy at artist
shops. Thus, you get a better coating to paint on, because the oil
paints adheres perfectly. Since the alkyd adheres strongly to the
acrylic layer, there is no risk of delamination.

In fact, Gamblin has an alkyd oil paint ground (Gamblin Ground) to which
has been added barium sulfate to provide tooth. They also give the
advice that pre-primed acrylic canvases should be coated with Gamblin
Ground. Since oil painters still use whites containing zinc oxide, it is
recommendable to use an alkyd ground, because zinc oxide adheres badly
to the acrylic layer, due to the formation of saponins. This could give
rise to delamination in the future.

So if you buy raw canvas, you only need to add two layers of alkyd
primer, which can be painted directly on the canvas. This provides a
much better ground than oil painters have had recourse to in earlier times.

Mats Winther
http://two-paths.com

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