Art Chowder September | October, Issue 17 | Page 41

S
ound documentation attests
that all the Pre-Raphaelites bought
(from Roberson) painting media
containing a natural resin similar
to, and often confused with Baltic
amber: copal.
Congo copal resin, unprocessed
photo: Melville Holmes
2018
The photo may give an idea of the fascination with liquifyinig a hard fossil resin as an ingredient in varnish and
oil paint media. Congo copal, dug from the ground in the former Belgian Congo was “the backbone of the varnish
industry” in the early-mid 20th century. It was the resin used in the Taubes Copal Painting Medium, before it was
discontinued in the 1980s, similar to the Roberson’s media used by the P.R.B.
Since “copal” is a generic term for
various resins from trees of fossil
and recent origin, the botanical
source of whatever resin was used
by the P.R.B. is unknown. Recent
scientific analyses of paint media in
their works suggest the presence of
copal resin in some form. It is highly
technical and the jury is still out, but
the elusive “x” might be, after all, a
natural varnish resin, perhaps even
of African origin, like the one used
in the finest carriage varnishes, the
hard copal from Zanzibar. 8
Advertisement for Roberson’s Medium
for Oil Painting, which contained copal
varnish, linseed oil, and mastic varnish
Chas. Roberson & Co. account books record
purchases of copal varnish and copal media by
all the Pre-Raphaelites.
see: Joyce H. Townsend et al. Pre-Raphaelite
Painting Techniques. Tate Publishing; 2004.
List of copal-based media P.R.B. members’ pur-
chases compiled by Leslie, Carlyle, pp. 63-64.
Endnotes
1 www.telegraph.co.uk/art/reviews/central-argument-show-proves-tenuous-extreme-reflections-van/ www.telegraph.co.uk/art/re
views/central-argument-show-proves-tenuous-extreme-reflections-van/
2 William. Holman Hunt. Pre-Raphaelitism and the Pre-Raphaelite Brotherhood. The Macmillan Company, 1905.
3 William Michael Rossetti, Dante Gabriel Rossetti: His Family Letters, with a Memoir. (London: Ellis, 1895) p. 135
4 )Wm. Holman Hunt. op cit.. p. 134, 136
5 Paul Coremans, et al. L’Agneau Mystique au Laboratoire. Centre National de Recherches “Primitifs Flamands”, 1953. pp. 124-126
6 Rachel Billinge and Lorne Campbell, “The Infra-red Reflectograms of Jan van Eyck’s Portrait of Giovanni (?) Arnolfini and his Wife
Giovanna Cenami (?).” National Gallery Technical Bulletin Volume 16, National Gallery Publications, 1995.
7 ibid.
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