STATE OF CONSERVATION

• The work shows signs of some yellowing in areas where a thick layer of paint that is somewhat different from the one underneath has been applied
• The paint layer is cracking in certain areas.
• There is some warping of the canvas caused by the contraction of the ground and paint layers.
• There are some rust colour stains caused by the rusting of the staples on the paint layer.
• There are some small brown particles - probably tobacco - in the paint layer.

Analysis of colour:
Readings were taken from certain near-white (slightly yellow or grey) points of the original work. Those points are shown in the figure below. Chromatic data are shown in the table underneath the figure.

The data shown in the table above suggest some yellowing of the paint surfaces, whether labelled as grey or yellow. The dominant wavelength was calculated for all readings, and it tends towards yellow.

On the other hand, the luminosity readings vary a great deal, probably because of the surface geometry (raised, flat, etc.).

For this piece, all the readings were taken from areas that had been equally exposed to light. As a result, there are no comparative data and it is therefore impossible to determine to what extent yellowing is due to the effect of light or to the chromaticity sought by the artist.

The diffuse reflectance curves shown in the diagram above do not provide any significant data either, since all of them are practically parallel. That suggests either simultaneous yellowing or a similar pigment and binder.

Sample reference number: 408/1

Sample description:
The sample consists of fibres taken from the support of this work. The aim of the analysis is to determine the type of fibres used and their morphology.

Analysis:
The sample was analysed under a scanning electron microscope (SEM). No presence of cotton, flax or hemp fibres was found in the longitudinal observation of this sample of the support canvas. It is worth pointing out that in previous reports on samples from this work the type of fibre determined, even though it was not absolutely clear, suggested that they were cotton fibres. However, in this case most of the fibres observed probably correspond to flax fibres. These findings are compatible bearing mind that he presence of both types of fibres in the support canvas is possible. That must be checked by an "in situ" observation of the areas from which the samples were taken.

SEM image of the set of fibres.
The clearest fibres correspond to cotton whereas
the fibres with knots correspond to flax or hemp

SEM image showing a detail of the fibres in which knots can be observed

Image showing a fibre corresponding to cotton
because of its longitudinal morphology

Sample reference number: 408/2

Sample description:
The sample consists of two white layers of paint. The surface of the top layer is fairly smooth and some darker areas were observed under an optical microscope. The bottom layer is more uneven in terms of thickness and has imprints of the support canvas.

Analysis:
The sample was analysed under a scanning electron microscope (SEM) and using Fourier transform infrared (FTIR) spectroscopy. The findings of these analyses show the presence of barium sulphate and zinc oxides in the ground layer and titanium oxides in the top layer. The binder is probably a PVA/VeoVa copolymer.

SEM image of the sample in which the two different layers can be observed.
The darkest one is the top layer and the brightest one is the ground layer.