I. Painter's Technique
The picture of St Claire from the North-East
recess of the Chapel of the Holly Rood can be considered
a typical example of Theodoric 's technique, beginning
with the beechwood panel made up of four parts, the joints
in which are strengthened by little pegs and pasted over
with strips of canvas. The two relatively thick ground
layers, the lower of silica and the upper of chalk, are
. limited to the area of the painting. The emphatic brush
drawing in black, partly visible to the naked eye, is
seen on the infrared photo to be quite different in the
composition of the folds from the painting, which is also
the case in the details of the face. These differences
are proof of a spontaneous creative approach.
The X-ray photo shows the typical signatory application
of lead white, which covers the drawing in horizontal
and sometimes slanting strokes and blocks the X-rays so
that the thin layer of the painting of the skin almost
disappears. The greyish tone of the carnation in the semi-shadows
and shadows is due toan admixture of black and also, as
is clear on the microscopic cross-sections, blue pigment.
The system of thin alyers of colour, the thickness of
which is not more than a few hundredths of a milimetre,
is documented by the microscopic cross-sections and the
analyses carried out in the National Gallery laboratory.
The crystalline natural azurite in the painting of the
cloak gives the material an inimitable blue-green shade.
The smooth modelling of the folds with the addition of
lead white on the highlights is made easier, as was shown
by the laboratory analyses, by the presence of an oil
medium in the tempera mixture. In the places where the
painting of the cloak extends onto the frame the layer
of colour tests only on an application of lead white,
which in style is the same as the application on the panel.
The frame, then, was not covered by other ground layers,
as was the background of the picture, where the relief
decor is on a ground layer of orange bound with oil.
Master Theodoric – St Clairre
ak. mal. Radana Hamsíková, AHVT B 035 (J. D.)