Historical Painting Techniques, Materials, and Studio Practice

pletely that it is difficult to distinguish between them. The lowest paint layer
(above the grayish wash of the drawing and the white ground) is the dark
undermodeling of the ebauche, containing Cassel earth, charcoal, and cobalt
blue. This is probably sufficiently dark in color to contribute to the observed
chiaroscuro of the dress (a similar mixture is used as a final glaze fo r the
deepest shadows) . The creamy mid-tone of the dress consists principally of
lead white, with traces of yellow ochre, Cassel earth, and cobalt blue; the
proportion of the tinting pigments is altered as one tone blends into the next,
however. The blending process is also reflected in the presence of a number
of paint layers in subtly different shades of cream in different parts of the
dress. Only in the lightest highlights is lead white used almost pure, ground
in walnut oil; even here, the presence of a trace of cobalt blue gives it coldness.
This general pattern of paint construction is repeated elsewhere in the painting.
Passages of paint containing a pigment used more or less unmixed are
very rare indeed, but in the red glazes supplying the purplish red of the
brocade dress, on the lap of the seated lady-in-waiting in Figure 6c, and the
shadows on the executioner's tights, a crimson lake pigment was used in this
way. In both cases, the dyestuff present was that extracted from a cochineal
insect, Dactylopius coccus Costa, on a substrate consisting largely of hydrated
alumina. The brown paint of the brocade, containing yellow ochre with other
iron oxides and black, contained ordinary linseed oil; the red glaze, however,
contained heat pre-polymerized linseed oil and a little mastic resin (Plate 34c).
This indicates the use of a varnish of the type recommended as a painting
medium, perhaps the jellylike vernis des Anglais described by Merimee as being
particularly suitable fo r glazes because it could be brushed on so easily (38).
The presence of a resin-containing medium is also suggested by the whitish
fluorescence exhibited by the glaze layer in ultraviolet illumination under the
mIcroscope.
The paint used for the red of the executioner's tights is perhaps surprisingly
complicated, as it contains two red lake pigments mixed with vermilion and
lead white (Plate 34a). Examination under the microscope suggests that one
is the cochineal lake used in the glaze; the other, less crimson in color, was
not present in sufficient quantity fo r analysis, but its pronounced orange-pink
fluorescence in ultraviolet illumination suggests that the dyestuff may have
been extracted from madder root, the use of which was being developed in
France at the time (39). Curiously, the same lake (mixed with black and cobalt
blue) is used rather than the more crimson cochineal lake for the attendant's
purple dress. Even the velvety black of Sir John Brydges' garment is a mixed
color: it contains a subtle combination of black, Prussian blue, red lake, and
a translucent yellow pigment (Plate 34d). This combination is similar to
Edouard Manet's tinted darks in Music in the Tuileries Gardens, painted thirty
years later (40). Quite marked brushwork is visible in the black garments of
Sir John and the executioner; analysis shows that Delaroche used a varnishtype
painting medium of similar composition to that used for the red glaze,
which retained the texture of the brush strokes.
To summarize, Paul Delaroche painted a grisaille of his composition and then
colored it in; the labor necessary to produce the finished painting was, however,
considerable barely revealed on its bland surface. The painter's craftsmanship
and understanding of materials cannot be denied; his reliance on
lead white and ochres in particular and the absence of bitumen have resulted
in a paint film in remarkably good condition, considering the recent history
of the painting. The use of a varnish-type paint medium has often proved to
be a recipe fo r disaster; in this case the paint shows few of the defects often
caused by its use. Delaroche appears to have added only cobalt blue and
synthetic ultramarine (and possibly an improved madder lake) to what could
be described as a conventional eighteenth-century palette.
The production of the Salon painting was not the end of the story. Public
awareness of successful Salon paintings was increased by means of reproductions
in the press; several of Delaroche's paintings, including Children of Edward
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Historical Painting Techniques, Materials, and Studio Practice