SILVERPOINT DRAWINGS OF ALBRECHT DÜRER: PIXE AND SY

SILVERPOINT DRAWINGS OF ALBRECHT DÜRER:
A COMPARISON OF PIXE AND SY-XRF *
P. Milota1, A. Duval2, I. Reiche2, O. Forstner1, H. Guicharnaud2, W. Kutschera1, S. Merchel3, M. Schreiner4,
E. Thobois5, B. Wünschek1, R. Golser1
1) University of Vienna, Faculty of Physics, VERA Laboratory, A-1090 Vienna, 2) C2RMF UMR 171 CNRS, Louvre, F-75001 Paris,
3) BAM, D-12205 Berlin / present address: CEREGE 6635 UMR CNRS, F-13545 Aix en Provence,
4) Academy of Fine Arts, A-1010 Vienna, 5) Albertina, A-1010 Vienna
INTRODUCTION
Nr. 4839
Our research group is particularly interested in the analysis of silverpoint drawings by Albrecht Dürer (14711528). A very sensitive and non-destructive analytical method, either spatially resolved synchrotron-induced X-ray
fluorescence (SY-XRF, fig. 1) [1] or proton-induced X-ray emission (PIXE) [2] is needed to determine the chemical
composition of such drawings. To amend the existing French-German data base we were analyzing such drawings
from the Collection of the Albertina, Vienna. Therefore, an external-beam PIXE setup (see fig. 2) was installed at
the Vienna Environmental Research Accelerator (VERA). It allows to analyze a spot of ~0.1 mm on the object in
air with 3 MeV protons, and to detect the emitted X-rays that are characteristic for the chemical elements with very
good sensitivity. After successful measurements on test samples, we investigated the silverpoint drawings “Girl in
Costume of Cologne; Agnes Dürer“ (1521, Inv. Nr.: 22385 D143) and “Lying Lion“ (1521, Inv. Nr.: 22385 D143v)
from Albrecht Dürer’s sketchbook of his journey to the Netherlands. The sketchbook from 1520/21 was split in
the 19th century and the 27 drawings, well documented in Dürer’s diary [3], are now conserved in several graphical
collections. We compare our new results to previous PIXE (Paris) and SY-XRF (Berlin) measurements on other
drawings from this sketchbook [4]. Up to now, only one work from an earlier period, “Willibald Pirckheimer” (1503,
Inv. Nr.: KdZ 24623) has been analyzed [5]. This portrait shows a significantly different silver mark composition
as compared to drawings from 1520/21. To answer the question what silverpoint Albrecht Dürer used in earlier
work, we investigated the drawings “Selfportrait at thirteen” (1484, Inv. Nr.: 4839) and “Portrait of the Artist’s
Father, the Goldsmith Albrecht Dürer the Elder” (dated ~1486, Inv. Nr.: 4846) from the Albertina.
Nr. 22385 D154v
30
KdZ 24623
KdZ...Berlin
152... Frankfurt am Main
89... Chantilly
223+48... Albertina
25
SY-XRF Berlin
PIXE Paris
PIXE Vienna
4
3
KdZ 33r
22385
22385v
KdZ 34v
KdZ 33v
15269r
KdZ 35v
KdZ 35r
891(314)r
892(315)v
15.7.1521
8-29.6.1521
10.4.1521
10-11.4.1521
10-11.4.1521
11.2-16.3.1521
3-7.12.1520
24.11-3.12.1520
3.12.1520
Beg. Dec. 1520
7-23.10.1520
Oct.1520
Oct. 1520
7.10.1520
1503
1486
0
Nr. 4846
1
892(315)r
893(316)r
5
893(316)v
KdZ 4179
4846
10
4839
In recent investigations 15 drawings of the Dürer sketchbook (Reiche et al. [1], Duval et al. [2]) were analyzed by
SY-XRF at BESSY in Berlin and by PIXE at AGLAE in Paris. Typical spectra can be seen in figs. 3 and 4. Our new
results by PIXE at VERA, on two additional drawings from the sketchbook confirm that the value of Cu in the
silver marks -averaged over all drawings- is (10 ± 3) wt.%. In figure 5 we compare our results for the silverpoint
drawings “Girl in Costume of Cologne; Agnes Dürer” and “Lying Lion” to the previous measurements on other
drawings from the sketchbook by SY-XRF and by PIXE, respectively. The analyzed drawings from the Albertina
fit nicely into the overall picture and support the perception that all drawings during the journey to the Netherlands
1520/21 were made with the same silverpoint. However, for three measurement points in the drawing “Girl in
Costume of Cologne; Agnes Dürer” we have evidence for the use of a different silverpoint with about
10 wt.% Cu and 4 wt.% Zn (see red points in fig. 5). The zinc could in principle be of external origin, but exactly
this composition was also found in one part of the sketchbook drawing “Sitting Bishop; Portrait of a Man with a
Fur Cap” (1520/21?, Inv. Nr.: KdZ 34r), the one part (“Man with a Fur Cap”) which was most likely not produced
during the journey.
15
1484
RESULTS AND DISCUSSION
wt.% Cu
20
Average composition
6.5±1.4 wt.% Cu
0.7±0.7 wt.% Zn
93.4±1.4 wt.% Ag
Nr. 22385 D143
6
2
1
2
Measurement points 2, 4, 8
12.3±0.5 wt.% Cu
4.2±2.1 wt.% Zn
87.4±7.1 wt.% Ag
Fig. 1: SY-XRF setup at BAMline/BESSY with drawing by Hans Holbein the
Elder. (1) Si(Li) detector covered with a thin Al or polyethylene filter. (2) longdistance microscope to observe the analytical points. X-ray source is a synchrotron equipped with a superconducting wavelength shifter (beam size about
100x200 μm2, X-ray energy about 30 keV).
Fig. 2: Key elements of the external beam PIXE setup during analysis of
“Portrait of the Artist’s Father” Albrecht Dürer, Albertina, Vienna.
(1) Beam collimating system covered with a Si3N4 exit window (beam diameter about 150 μm). (2) Si(Li) detector with additional 150 μm Kapton®
window. (3) SDD detector with additional 150 μm Kapton® window. (4)
Laser for positioning the object. (5) Miniature video camera and Firewire
camera (can not be seen on this picture) equipped with a macro lens.
105
105
Ca KD
Silvermark
Paper backing
Silvermark
Paper backing
Ca KE
104
104
PbLD
AgKE
PbLE
SrKE
CuKD
HgLD
103
Counts
Counts
FeKD
103
AgKD
SrKD
CaKD
Ar KD
Ag LD
Fe KD
Cu KD
102
HgLE
Hg LD
Zn KD
PbLJ
Hg LE
Pb LD Pb L
E
101
102
Ag KD
Sr KD
Ag KE
100
101
0
2
4
6
8
10
12
14
16
18
20
22
24
26
Energy [keV]
Fig. 3: SY-XRF spectra of a silverpoint mark (blue line) and of bone white ground
layer (black line) from “Sitting Bishop and Portrait of a Man with a Fur Cap”
recorded with a Si(Li) detector at BAMline/BESSY (see setup above).
0
2
4
6
8
10
12
14
16
18
20
22
24
26
Energy [keV]
Fig. 4: PIXE spectra of a silverpoint mark (red continuous line) and of
bone white ground layer (black dotted line) from “Agnes Dürer” recorded
with a Si(Li) detector (see setup above).
ACKNOWLEDGEMENTS
We wish to thank K.A. Schröder, Albertina, Vienna, for providing access to Dürer’s drawings. We acknowledge the cooperation with H. Riesemeier, M. Radtke,
and A. Berger, BAM, Berlin. We wish to mention the support by J. Salomon, L. Pichon, S. Roehrs, AGLAE, Paris, by A. Priller, P. Steier and A. Wallner, VERA,
Vienna, by C. Streli, P. Wobrauschek, TU Vienna, and by O. Benka, University Linz. Part of this work was funded by University Vienna (IP 517001), ÖAD
(Amadée 2005-2006), COST G8, and EU-ARTECH.
Fig. 5: Upper left panel : “Selfportrait at Thirteen” (1484). Upper right panel: “Lying Lion“ (10.4.1521). Lower left panel: “Portrait of the Artist’s Father, the Goldsmith
Albrecht Dürer the Elder” (dated ~1486). Lower right panel: “Girl in Costume of Cologne; Agnes Dürer” (15.7.1521), blue circles indicate measurement points on the
marks, green circles measurement points on the ground layer, and red circles indicate marks where another silver alloy was measured. The graph shows the concentration
of Cu in the silver marks from the Netherlands sketchbook measured by SY-XRF and PIXE, respectively. For comparison, SY-XRF data from “Willibald Pirckheimer”
(1503) and PIXE data from the two portraits are included. The abscissa gives the dates of the drawings together with their inventory number of the respective museum.
CONCLUSIONS
The new PIXE measurements at VERA confirm the use of a silverpoint as the main drawing tool in all analyzed drawings. Our
results support the previous assumptions by Reiche et al. [1] that the drawings of Dürer’s sketchbook from 1520/21 were made
with one type of silverpoint: a silver alloy containing about (10 ± 3) wt.% of Cu, and a very low content of Zn (1.0 ± 1.2 wt.%).
Of particular interest is the comparison of the silverpoint used for the early drawings “Portrait of the Artist’s Father” and the
“Selfportrait”. From the analytical data we have no reason to assume the use of different silverpoints. Our measurements not
only yield a very similar composition, it is also strikingly similar to the silver alloy used in the later work of 1520/21. Obviously,
the silverpoint used in “Willibald Pirckheimer” (1503) is markedly different. Thus, the copper concentration alone will not
help to distinguish between Dürer´s early and late silverpoint drawings. The complexity of the drawing materials and of the
drawing technique found for the “Portrait of the Artist’s Father” requires further measurements. We conclude that two
different methods in three different laboratories give consistent results on Dürer´s silverpoint drawings from the
sketchbook. The new PIXE setup at VERA opens up new possibilities for non-destructive elemental analysis in Austria.
Thus, it complements the established techniques in other laboratories for the investigation of very precious objects of art.
REFERENCES
[1] I. Reiche et al., Following the traces of Albrecht Dürer: analysis of silverpoint drawings by spatially resolved synchrotron induced X-ray fluorescence analysis.
Nucl. Instr. and Meth. in Phys. Res. B226 (2004) 83-91.
[2] A. Duval et al., Particle induced X-ray amission: a valuable tool for the analysis of metalpoint drawinngs. Nucl. Instr. and Meth. in Phys. Res. B226 (2004) 60-74.
[3] H. Ruppich, Dürer Schriftlicher Nachlass, Deutscher Verein für Kunstwissenschaften, Berlin (1956) 202.
[4] I. Reiche et al., Non-destructive investigations of Dürer’s silver point drawings by Pixe and μ-SR-XRF. Art 2002 - 7th International Conference on Non-destructive
Testing and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage, Antwerp, Belgium (2002) 82.
[5] I. Reiche et al., Spatially resolved synchrotron-induced X-ray fluorescence analysis of metal point drawings and their mysterious inscriptions. Spectrochimica Acta
Part B 59 (2004)1657- 1662.
[*] XIth IADA Congress -50th Anniversary of IADA: 17. - 21. September 2007, Vienna.
V ER A
Vienna Environmental Research Accelerator
Isotope Research
Faculty of Physics