As
much as it pleases us to see so many positive comments about Liquin
in December's Varnish Guide
(TAM, To Preserve and Protect, December 2004), we'd be remiss if we didn't point out that Liquin
isn't intended for use as a varnish. Because Liquin is
used as a medium by so many artists to speed the drying of the paint layer, it has been an
easy conceptual leap for many to presume that a layer of Liquin on top is just as good as
Liquin added inside. It's not. Since its introduction in the 1960's, Liquin has been, and
always will be, intended only for use as a medium. The problem with Liquin isn't the
clarity or the resiliency of the film (it has both of those in abundance); it's
that it dries too darn fast and to a solid and highly impermeable film.
If used to seal a still-wet paint layer, Liquin will fully block any further
access to the atmosphere and the oxygen that is absolutely essential to the drying of the
paint film. Without oxygen, the oil is incapable of forming all those nifty
linkages that turn it into a highly durable layer. The paint layer will never fully dry,
eventually proving unstable in a number of ways. Moreover, Liquin isn't soluble or
removable (at least not in a way that leaves the painting beneath intact), making it
virtually impossible for a conservator or restorer to work on the paint film when needed
at a later date.
The key to varnishing
requires a quality that is increasingly difficult to find in today's "I need it
now" culture: patience. The paint film really, truly does require 6
months (at least) to add all those bits of oxygen. There's nothing that will effectively
accelerate the entire oxidation process or make the oil 'hyperventilate.'
Note: Many of you will remind me that an alkyd resin like Liquin speeds
the touch dry point. And you're right. But it's unable to accelerate the full oxidation of
the entire layer, and anything that gets in the way of the oxidation process is going to
compromise the long-term stability of the painting. If absolutely necessary, a retouch
varnish can be added 30 days after the piece has been completed.
The best choice for varnishing
is a synthetic resin varnish, as opposed to Dammar, which - with all due
respect to what Ralph Mayer wrote before synthetic resin varnishes were invented - will
yellow, embrittle, and become increasingly difficult to remove as it ages.
That and a little patience.
David Pyle
Director of Communications & Technical Education Winsor & Newton
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