Varnish removal – and a faux marble discovery

March 17, 2010

Artists and house painters apply a varnish to protect their paintwork and to give the surface an even sheen and a high saturation. They dissolve a bit of a resin in a solvent. Mastix or Damar or Copal resin for example, dissolved in turpentine. Or Shellac in alcohol. Or a bottle of Artist’s Varnish readymade from the shop. The solution is brushed on, the solvent evaporates, the translucent layer is applied.
But is doesn’t stay like that.

All sorts of chemical processes are going on after the painter leaves. The varnish discolours, becomes brittle, and slowly turns into a dark veil with the craquelure pattern of a crocodile skin, or a muddy path after a few dry summerdays. And obscures the paintwork underneath.

Sometimes the old varnish becomes so dark over time that people forget what the painting was. Because it isn’t visible anymore, at all.

To remove an old, brittle varnish is not always easy. The right method needs to be found, the right solvent, the right tools so that the varnish is removed and the underlying paint is not affected. Do we need cotton swabs, gel tissues, mechanical means? Is the solvent just swelling the varnish, or does it get through to the paint layers? What happens to the support, the plaster, or canvas?

And after using the head and the hands, this is what can be discovered: a painted red marble that everybody forgot about, but was there waiting since the late nineteenth century to be admired again. And in the photograph, just below the colour chart, the brown darkness is waiting to be removed.