Page 225 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

P L A T E 65 Scheele's green from the Forbes pigment
collection. The sample shows light green biréfrin­
gent particles of I less than 1.662 (melt-mount
R
R I 1.662, magnification x325).
P L A T E 66 Photomicrograph of phthalocyanine
blue. The deep blue color of the pigment is easily
visible even in a mounted preparation, and the
intensely colored particles resemble Prussian blue
(melt-mount R I 1.662, magnification x347).

P L A T E 67 Frans van Mieris the Elder (Dutch,
1635-81) , Pictura {An Allegory of Painting), 1661.
H
Oil on copper, : 12.5 cm (arched top); w: 8.5 cm.
In the painting, , the allegorical figure is shown
A
holding a palette with seven different colors. Scan­
ning X-ray flourescence analysis revealed the fol­
65 lowing elements in various areas of the painting:
Β, copper and lead in the palette area; c, iron, man­
ganese, calcium, and mercury in the face area; and
D, calcium, iron, mercury, and tin in the palette.
Maps for copper and lead in Β reveal part of the
copper sheet and the lead-white ground. The
higher concentration of lead in a series of hori­
zontal and vertical lines indicates where the cop­
per surface was scored to improve adhesion of the
ground to the metal. Los Angeles, J. Paul Getty
Museum (82.PC.136) .

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