Series editors' preface - Wood Tools

746 Conservation of Furniture
(a)
Figure 16.15 Effect of discoloured varnish
(a) A fancy painted chair, Baltimore, early nineteenth century, during conservation. Darkened and degraded varnish
(right front leg) gave an entirely different effect from the original paint scheme, revealed on the left front leg
(b) Detail of the seat rail of the chair, before conservation
(c) Detail of the seat rail of the chair, after conservation. Removal of discoloured varnish with an enzyme gel
revealed an elaborate decorative scheme
aesthetic. The decision to remove a discoloured
varnish layer should be made in consultation
with the owner or curator, and may
be influenced by whether such a coating was
part of the original surface. An original coating
may be left intact even though it has discoloured
whilst a similar non-original coating
may be more likely to be removed. The services
of a paint analyst or microscopist skilled
in the analysis of historic paint films may be
helpful. The removal of a coating from a
painted surface is a major conservation treatment
and should be undertaken only with the
guidance of an experienced specialist.
Treatment options for the removal of varnish
from painted furniture will depend on the
nature of the binding media. A wide range of
(b)
(c)
binding media have been used on painted furniture,
including drying oils, resins, egg white,
egg yolk, gums, glue size, oil and beer. Casein
paint was usually prepared by mixing milk
curd with an alkali. The resulting material
could be used as an adhesive or as a binder
for paint. In some cases, for example on vernacular
furniture, milk paint was made by simply
mixing pigment with milk. The proportion
of pigment could be as high as 10%. The
options for treating an oil-based paint are different
to that for a distemper, a mixed media
finish such as graining or marbling, or a surface
composed predominantly of pigmented
natural resins.
The responsible removal of varnish layers
from painted furniture requires accurate identifi-