Coating on Henry Moore model

I would like to have a better understanding of the ageing
characteristics of a water-soluble pigmented wash unevenly applied
to our Henry Moore fibreglas model, "Standing Figure: Knife Edge",
1961.

Malcolm Woodward, a sculpture consultant to the Henry Moore
Foundation, kindly provided general information. "The fibre-glass
was coloured with "walnut chrystal" [sic], a powdered material that
Henry Moore used for colouring white plasters to give them some
'modelling'. It is a water-based medium but unfortunately it has
been replaced by a more synthetic medium which is still called
walnut chrystal but is an unsatisfactory replacement because it is
now more like a dye than a stain."

In an early publication, "Staining and Polishing", Charles Hayward,
1946 London, I was able to find a reference to the traditional stain
"Walnut Crystals", made from Vandyke crystals and water, darkened by
the addition of a little ammonia.  I suspect that the proprietary
stains were based on this idea but modified, as was the spelling of
"chrystal".

As we await the results of scientific analysis, I am wondering if
anyone can provide any particular insights concerning the
water-based or later synthetic "Walnut Chrystal".

Sandra Webster-Cook
Conservator
Art Gallery of Ontario
317 Dundas St. West
Toronto, Ontario M5T 1G4   Canada
416-979-6660 ext.331
Fax: 416-979-6670

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                  Conservation DistList Instance 12:45
               Distributed: Wednesday, November 18, 1998
                       Message Id: cdl-12-45-006
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