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4.3.1 PAINTING MEDIA AND PAINT STRATIGRAPHY

Following Italian tradition of ‘gesso’, the panel has a light (off-white coloured)
ground made from gypsum (calcium sulphate). To determine the binding
medium used, on two samples the ground was mechanically separated from
the remaining paint layers with the aid of a stereomicroscope and subsequently
analysed with GC-MS. The detection of amino acids suggests that an animal
 glue was used to bind the gypsum, although due to the small sample
size a more precise classification of the proteinaceous binding medium was
not possible.
To prepare a surface that was as flat as possible for the application of paint,
this underlayer was sanded (in alternating directions) in multiple working
steps. To prevent the absorption of the precious paint, but also to achieve
a high light reflection and thereby great luminosity for the paint layers, an
overall layer of lead white, the so-called imprimitura, was laid over the
highly absorbent ground. Using SEM/EDX, in many of the cross-sections
some tin could also be determined along with the main lead signal in the
imprimitura: hence, a small amount of lead-tin yellow was added to the
lead white.
Through detailed study of the painting (especially in raking light), both the
initial consistency of the imprimitura layer and its method of application
can be evaluated. The imprimitura was distributed over the ground with a
broad brush; the striated texture of the thick paint is clearly recognizable
in the x-radiograph due to the high lead content and occasionally also in
visible light (see fig. 8).
The paint structure above is characterized by the overlapping of many thin
layers. An opaque layer usually follows the imprimitura, thin enough to not
wholly mask its luminosity. Further modelling occurred through the
application of multiple glazes, with coordination of the colouration of the
opaque underpaint and the translucent layers above. Hence, for example,
an opaque red underpaint of lead white with vermilion was followed by
medium-rich layers of red lake (fig. 28); above an opaque layer of lead white,
lead-tin yellow, and carbon black, copper green glazes were applied, likewise
with a high proportion of binding medium (fig. 29).
From the layer sequences of the two cross-sections illustrated here, it is also
evident that Garofalo usually worked from darker to lighter tones. When
necessary, local highlights of reflected light are placed on the glazed layers
in thick, opaque paint (impasto).
Of the colourants used it can be determined that Garofalo’s palette in this
painting is characterized by the brilliant, highly luminous colours typical
of the artist. Through the skilled combination of pigments and dyes he
achieved a variety of tones and thus nuanced colour effects.

RESURRECTION

OF CHRIST