STATEMENT ON THE PAPER RESEARCH PERFORMED ON A
PASTEL WITH TWO BATHERS
1 The
investigation. In
the year 2002 the undersigned, Adriaan Kardinaal, investigated, in collaboration with dr Henk Porck
(Dutch National Library),
the paper of a pastel drawing, ascribed to Pierre Auguste Renoir and owned by Mr Gregory Kitchen. The
investigation consisted of visual observation, fibre analysis, the use of various spectrometric and other scientific
techniques. Direct visual observation was partly aided by enlargement up to 50x and various types of light under different angles at the
Proost & Brandt Laboratory, as well as by means
of scanning electron microscopy (SEM) at the Netherlands Institute for Cultural
Heritage (
The chemical composition of paper and coating
was analysed by way of X-ray fluorescence spectrometry (XRF), the exact
location of the relevant elements (paper fibres or coating) by scanning electron microscopy combined with
X-ray spectrometry (SEM-EDX); further data were added by infrared spectrometry
(FTIR), liquid chromatography (HPCL) and gas chromatography-mass spectrometry
(GC-MS) and spot testing. All of these tests were done at the Institute for
Cultural Heritage.
Finally, fibre analysis was performed by Georgine Calkoen from the Proost & Brandt Laboratory. The main results of the investigation, as written in the report submitted to Mr Kitchen, concern:
-
the
type and production date of the paper
-
the presence or absence of a print, photographic
or otherwise.
2 Type and production date of the paper.
The paper consists of bleached sulphite fibres and a very thin coating of gelatine and
starch. No internal sizing is present. On this basis the paper of the pastel
was identified as transfer paper, a type of paper used by artists to make
drawings that could later on be transferred to stone for lithographic printing
or to metal for letterpress printing.
The paper has once been attached to board. This
was a necessary step to keep it flat for the purpose of drawing as the paper
curls very easily along the fibre direction. The artist of the pastel did not
choose a paper very suitable for pastel drawing because of the smoothness of
the coating but which must have suited him for artistic reasons: the white
colour of the coating is part of the colour composition of the pastel.
It was further concluded that the paper was
produced in the nineteenth century. This conclusion was based upon the
appearance as well as the chemical composition of the paper. For instance, the
absence of calcium suggests that fibre bleaching was done by chlorine gas, a
common method in the nineteenth century, but generally replaced by bleaching
powder (calcium hypo chlorite) towards the end of that age.
The date for the paper is also very likely the
date of the pastel drawing as transfer paper has no special feature why a stock
of it should be kept for later use.
3 The presence or absence of a print. In
this respect there are two possibilities:
(i)
a
photographic print
(ii)
a
graphic reproduction
In case of the presence of a photograph under
the pigment layer of the pastel, certain chemical elements would have to be
present: silver, chromium (for the carbon process), iron (for the cyanotype
process). We systematically searched for these elements but none was found.
This effectively excludes the presence of a photograph under the pastel layer.
If a graphic reproduction or a photograph would
be present on the investigated paper, its source must be the drawing by Renoir
of three bathers, now in the Musée d’Orsay, which, apart from the extra bather, most closely
resembles the pastel. There are however differences between the pastel and the
drawing in the Musée d’Orsay
both in the structure of the background, in some anatomical details and in the
mutual position of the two remaining bathers. Therefore, in case of a graphic
reproduction printed on the investigated paper, a diverging composition should
be present under the pastel image. No such diverging image was found when the
pastel was inspected with transmitted light even though the whole object is
very transparent. Neither did investigation with infra red reflectography
show any sign of divergence from the pastel drawing.
Amsterdam 30-9-2007