Scientific study of Barcelona Rooftops
Four samples of paint were taken for the scientific study of Barcelona Rooftops, which involved several phases of analysis and the use of combined techniques (optical and scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy) and chromatographic techniques for the identification of organic components. The samples were examined and photographed with a binocular magnifying glass, in order to choose the most representative fragment of the complex layers.[1]
As a result, the range of colours used in the visible image of the Barcelona Rooftops can be distinguished from those in the scene depicting the couple, which is much brighter as befits the chromatism of his first journey to Paris (figs. 16 and 17, p. 50).
The study was carried out from the surface inwards, i.e. from the visible layer to the underlying layers, and concluded that the work is a stratigraphically complex composition apparently executed in two phases.[2]
The structure of the visible image is made up of several superimposed layers, ranging from dark to clear. There are signs that the first dark layer was applied to a large surface area, which leads us to think that the artist intended to cover the earlier image (the X-ray films show the marks of the spatula used to remove the excess fresh paint). On this layer of darker blue Picasso drew the buildings in pale blue and silhouetted them in the darker shade.
The combination of stratigraphic studies and microscopic observation of the fissures in the layers of paint allow us to conclude that the individualised colours of the first underlying layer are related to his 1901 palette. As to how the paint was applied, the brushstrokes are neither Pointillist nor fragmented but long, covering and textured. The figures present blends of pigments, and the flesh tones emerge from the combination of white lead and vermilion, with traces of cadmium yellow. This colour was not applied directly to the blank canvas, as the stratigraphic study reveals an earlier reddish-brown layer that is not an earthy colour but a complex blend of green, red and slight tinges of blue and yellow. Picasso silhouetted the couple in pure pigments, as he had begun to do in works of 1901 such as the portrait of Mañach. The canvas chosen to paint Barcelona Rooftops was a commercial preparation consisting of calcite, zinc white and white lead.
Nevertheless, he apparently applied a white imprimatura before the colour, as can be deduced from the stratigraphic analyses.
As no clear third layer has been found, we can contend only that there were two pictorial phases. In the first (visible) phase we have established the presence of Prussian blue, red iron oxide, vermilion, hydrated iron oxide, white lead and cadmium yellow (traces). In the second (non-visible) phase we have discovered red lacquer, vermilion, viridian green, white lead, cadmium yellow (two yellow and orange pigments) and ultramarine blue, and two other pigments, Prussian blue and red iron oxide.
[1] Characterisation of pigments: PATRIMONI-UB. Historical Heritage studies, Universitat de Barcelona (Sarah Boularand, Judit Birosta, Màrius Vendrell and Pilar Giráldez).
[2] See the location of samples and the description of pigments, pp. 52–55.
13 / 18
Summary