The Manuscript Codex * Materials
VERDIGRIS

The pigment copper acetate, used in a green paint. The presence of copper in a pigment often causes characteristic browning and brittleness in the areas of the support to which the paint is applied. The name verdigris is widely, but wrongly, applied to any green paint in which such damage is observed. These green and sometimes blue-green paints are complex chemical compounds made in different ways, using different ingredients. What they share is the presence of copper, and it appears to be salts of copper that cause damage to the support. Consequently, unless a pigment has been positively identified through analysis, it is more accurate to refer to it as probably containing copper.
 
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UBL OR. 241

 

AUTHORS: PAUL HEPWORTH AND KARIN SCHEPER