National Gallery Technical Bulletin Volume 9, 1985

Analyses of Paint Media

John Mills and Raymond White

The results reported in the Table were obtained by our usual gas-chromatographic methods (note 1 and earlier papers there cited) supplemented by the use of gas-chromatography-mass-spectrometry wherever possible (note 2). All detections of resin involve the use of the latter technique.

Notes to the Table

1. This painting and some associated panels have been the subject of an article in Volume 8 of this ‘Bulletin’ (note 3). We cannot be sure that the apparent presence of oil in sample 2 is an original feature, it may represent the remains of absorbed old oil varnish.
2. The pine resin detected in sample 2 comes presumably from the presence of 'copper resinate' pigment. The use of oil with 'copper resinate' in paintings otherwise wholly in egg tempera medium has also been noted by others (note 4). This painting has been the subject of an article in Volume 8 of this ‘Bulletin’ (note 5).
3. Traces of pine resin were detected in samples 1, 5, and 6 but were absent in samples 2 and 4. Sample 3 was not examined by GLC-MS. As there was no more in the green sample than in the others it seems likely that these represent traces of residual old varnish rather than components of the paint.
4. The rather weak azelate peak in samples 2 and 3 (about half the height of the palmitate peak) definitely suggests the presence of egg as well as oil, perhaps in the underlayers, but we did not confirm this by staining tests.
5. The P/S ratio for this and the following painting by Detroy indicates walnut as the most probable oil type, but as only one sample was examined in each case and the result is near the borderline for walnut and linseed oils some doubt remains.
6. Samples were examined from this painting as it had proved potentially vulnerable to solvents used for varnish removal. Pine resin was found as indicated and the medium would seem to have been essentially of the resin varnish plus oil form, possibly used for its quick-drying properties.

References

1. Mills, J. S. and White, R., 'Analyses of Paint Media', ‘National Gallery Technical Bulletin’, 7 (1983), pp. 65–7.
2. Mills, J. S. and White, R., 'Organic Mass-Spectrometry of Art Materials: Work in Progress', ‘National Gallery Technical Bulletin’, 6 (1982), pp.3–18.
3. Gordon, D. and Reeve, A., 'Three Newly-Acquired Panels from the Altarpiece for Santa Croce by Ugolino di Nerio', ‘National Gallery Technical Bulletin’, 8 (1984), pp.36–52.
4. Johnson, M. and Packard, E., 'Methods Used for the Identification of Binding Media in Italian Paintings of the Fifteenth and Sixteenth Centuries', ‘Studies in Conservation’, 16 (1971), pp.145–64.
5. Braham, A. and Wyld, M., 'Raphael's "S.John the Baptist Preaching" ', ‘National Gallery Technical Bulletin’, 8(1984), pp.15–23.

Artist	Picture	Date	Sample	Medium	P/S	Oil type	Note	
Ugolino di Nerio	David (panel from an
altarpiece)
No.6485	c.1325	1. Blue robe
2. Raised brown base for gilding	Egg
Egg + oil			1	
Attrib. to Ercole de'
Roberti	The Last Supper
No.1127	Last quarter
15th cent.	1. Brown, bottom edge
2. White tablecloth	Egg
Egg	
			
Preda	Portrait of F. Di
Bartolomeo Archmto
No.1665	1494	1. Blue doublet
2. Green mantle	Oil
Oil	3.0
3.3	Walnut
Walnut		
Raphael	S.John the Baptist
Preaching
No.6480	1505	1. Blue sky between trees
2. Green tree foliage, top L.H.
edge	Egg
Oil + resin	2.7	
Walnut	2	
Bronzino	Madonna and Child
with the Baptist and
S. Anne
or S. Elizabeth
No.5280	Mid-16th cent.	1. Red lake
2. Red lake (second sample)
3. Christ's flesh
4. Green landscape
5. Blue of Virgin's scarf
6. Blue of Virgin's robe	Oil
Oil
Oil
Oil
Oil
Oil	3.0
2.6
2.9
3.1
3.0
3.0	Walnut
Walnut
Walnut
Walnut
Walnut
Walnut	3	
Pellegrini	Rebecca at the Well
No.6332	c. 1708–11	1. Pink Cloud
2. Red
3. Grey-green	Oil
Oil
Oil	2.2
1.8
1.6	Linseed
Linseed
Linseed		
Bouts	The Virgin and Child
No.2595	1460s(?)	1. Red damask
2. Virgin's blue robe
3. Green cushion	Oil

Oil(+ egg?)
Oil (+ egg?)	1.7
1.8
1.9	Linseed
Linseed
Linseed	4	
Attrib. to Vigée-le
Brun	Self Portrait
No.1653	1742	1. Blue sky	Oil	2.4	Walnut?	5	
Detroy	Jason Swearing Eternal
Affection to Medea
No.6330	1743	1. Beige, lower edge	Oil	2.3	Walnut?		
Le Prince	The Necromancer
No.5848	1775(?)	1. Red-brown edge
2. Grey-green edge	Oil + resin
Oil + much
resin	2.0
2.0	Linseed
Linseed	6	
Ingres	M. de Norvins
No.3291	1811	1. Red-brown background
2. Black coat
3. Red drape, top edge	Oil
Oil
Oil	1.6
1.8
2.3	Linseed
Linseed
Linseed?		

Garry Thomson, Scientific Adviser
Martin Wyld, Chief Restorer
Ashok Roy: Editor

© 1985, The National Gallery, London

ISBN 0901791 97 0
ISSN 0140–7430

Designed by James Shurmer

Printed by Westerham Press, Westerham, Kent