Colnaghi Foundation Journal 03 - Magazine - Page 172
170
Scientific intervention in two major Murillo canvases
Scientific intervention in two major Murillo canvases
for this is that the system fixing the first fabric strip to
the stretcher, in contact with the original, is not tacked
along the edge, but only held with adhesive. There are
cuts along the edge intended to eliminate distortion
when it came to be assembled. This fabric strip hides
the second which is secured all around the perimeter
with tacks. This intervention was probably done in
1902, when the works were taken down in their frames
and the new stretcher inserted, using the bars of the old
one as strengthening crossbars for the frames.
Apart from the strengthening of the canvases, a second
intervention is observable where the corners were stapled
and windows opened in the edges of the stretcher to view
and study the number of lining fabrics on each picture.
DIAGNOSIS AND INTERVENTION
In addition to the painter’s techniques, the research
element of this project allowed us to determine the
factors and processes causing the works to deteriorate.
It also indicated what had to be done to recover their
artistic qualities, with constant reference to the IAPH’s
specific methodology and criteria.
The stretchers are rectangular in shape (238 x 578 cm).
There are three vertical bars forming four areas. The
joints between the bars are dovetailed with a small case
for a double wedge. The crossbar contains a groove where
the vertical bar pin slots in, allowing it to slide up to the
case: some contain forged metal nails which act as stops.
The third vertical stretcher bar in The Miracle of the
Loaves and Fishes contains an inscription with the date
of two previous interventions and the names of the
individuals who carried them out. The first was done in
1902 by José Escacena, with help from his nephew, José
Octo. A second restoration was done in 1985 by the
Seville Cathedral team thanks to the patronage of Don
José María Benjumea, who donated proceeds from a
sale of books to pay for the intervention.
Fig 15 / Comparative study
using various techniques
(normal night, x-rays,
ultraviolet).
Fig 16 / Comparative study
using various techniques
(normal light, x-rays,
ultraviolet).
The stretchers were in good condition, although dirt
had built up, and there were cracks in some of the
wedges, as well as evidence of damage from Anobiidae
and Dermestidae (though the insects were inactive).
Orthophotography and subsequent study has shown
that in the stretcher of The Miracle of the Loaves and
Fishes, the central area of the lower crossbar curves
upwards slightly, and the corner joints do not meet
at ninety degree angles. In the upper part there is a
deviation towards the right of 5.4 cm.
In both pictures the original support consists of three
lengths of cloth, or strips, laid horizontally and joined
by a single seam, apparently stitched from the front
side. In both works, the cloth strips are arranged in a
similar manner, the smallest being placed at the top
and underneath the two larger strips. These correspond
approximately to the width of the loom used to weave
the cloth (111.55 cm at its widest). The total dimensions
of the canvases, taking into account the irregular edges,
are approximately 240 x 579 cm, since the original
fabric exceeds the size of the stretcher.
The works are lined with two cloth strips. In all the
picture supports the fibre is linen, with a strengthening
lining made from a type of taffeta: this is a simple way
of joining parts, used since classical times, easy to make
and acquire. The weave density in the lining fabric is
less than the original, the distortion in the threads of all
the fabrics being Z-shaped.20
Each lining fabric is made of two strips laid
horizontally, thus following the direction of the warp
and weft in the original. The strips in the first lining are
joined with a simple stitched seam, those of the second
lining are joined with an over-sewn seam. It is curious
to note that in the second lining of both canvases
there are weaving errors, with big basting stitches and
loops in the warp. The natural pattern of the taffeta is
inexistent in these areas, and so two similar movements
occur, producing in some parts an effect of double
threads which follow the direction of the warp.
The double lining was done in the same intervention
to ensure the required strength and tension in these
large format works. One of the key pieces of evidence
The tension of the supports is stable. The canvas
of Moses and the Water from the Rock of Horeb was more
lacking in tension and so showed greater distortion
of the fabric at the corners, due to the changes in
temperature and humidity where it was hung on the
north side of the building.
The degree of radiation intensity used to obtain an X ray
of the painting was sufficient to observe the preparatory
layers, priming (lead white), the paint layer and the
stretcher. It was, however, inadequate for observation of
the support fabric free from the layers on top of it, since
the weave in the areas where inorganic radiographic
charge is lacking is low density and thus not radioopaque and produces no contrast. In the radiographic
study there is no apparent original fabric on the vertical
edges of the sides of both canvases. This fabric carries
a whole stucco-work of interventions, which lack radioopaque charge and do not contrast. This can lead to
mistakes because there is an underlying support that
reaches the edge and at times overhangs the stretcher.
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Additionally, in The Miracle of the Loaves and Fishes the
shape of the losses led us to suspect breaks in the
original fabric; some of these are considerable, for
example in the area of the loaves and the area where
groups of people are resting. Some losses in the ground
layer and thin paint layer are also evident on several
faces, such as Saint John’s and the apostle wearing
a yellow ochre cloak; the figure standing behind the
apostle taking the basket of fish; the child carrying the
basket; the beard of the figure on the right leaning on a
staff; and the eye of the old woman in the bottom right
corner. Lastly, there are paint losses in the neck and
hand of the apostle seated on Jesus’s left.
There are, however, few losses indicated in the
radiographic study of Moses and the Water from the Rock
of Horeb: most are in the central area, specifically in the
figures placed in front of the rock, and these tend to be
small. The areas showing losses are Moses’s beard, the
hair of the woman drinking on the left, and the hair of
the child drinking from a bowl in the bottom right.
The preparatory layers and the paint layer are well
bonded together, forming a unit, but study with raking
light revealed the lack of adhesion between these layers
and the support, and even indicated that they were at
risk of becoming detached.
The chromatic alteration in the two canvases was
evident across the whole surface and caused by several
factors. Firstly, on exposure to visible and ultraviolet
light, it was clear that the varnish had turned yellowish
through oxidation. Secondly, re-touchings in the two
previous interventions in various areas, had changed
colour and appeared matte. Thirdly, there were small
flecks or whitish stains on the surface caused by an
opaque effect of the varnish, affected by damp.
