Watercolour on thin board

Lee Churchill <leec [at] glenbow__org> writes

>I am hoping to get feedback on options for treating watercolours on
>very thin acidic board.
>
>In our collection we have a number of works by an artist named
>Marmaduke Matthews (1837-1913). Several of the paintings are on what
>appears to be 1-2 mm thick 'Masonite' type boards.  If there is a
>paper layer it is very thin and is hard to determine, as in most
>cases the entire surface is covered with paint and the edges are
>often damaged, however, I think the paintings are straight on the
>boards.

Lee Churchill states the boards are like 'masonite'. This strikes me
as odd because the masonite I know of is dark brown in colour and
would not take watercolour at all. This suggests to me that there
must be a paper layer on top. The other problem with masonite is its
strength. It is very tough material and does not lend itself to dry
backing removal with scalpels and spatulas. My understanding with
masonite is that there is no adhesive involved, but it is made from
unbleached wood, so there would be undesirable materials present
such as lignin and resin.

I have removed watercolours that were executed on a proprietary
board which comprised a thick layer of poor quality card and a thin
layer of white paper pasted to the surface. The paper was the
thickness of cigarette paper. This made dry backing removal very
hazardous but it was possible. Ultimately I think it was worthwhile,
given the poor quality of the card. Once removed the watercolours
could be cleaned on the suction table and then backed with a high
quality Japanese paper.


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                  Conservation DistList Instance 21:27
                Distributed: Saturday, October 20, 2007
                       Message Id: cdl-21-27-002
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