III. Painting Technique and Restoration (PDF, 5,21 MB) - Koninklijk ...

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THE PRODIGAL SON
BY PETER PAUL RUBENS
III. PAINTING TECHNIQUE AND RESTORATION
Susan Farnell
with additional comments by Nico Van Hout
The recent restoration
The Prodigal Son has just been restored. It was in good condition but the
restoration was necessary because it was becoming increasingly difficult
to see the painting through the layers of thick and discoloured varnish.
Rubens must have intended the dramatic perspective of the view through
the barn to give an added sense of depth to this composition while also
experimenting with the effects of daylight and candlelight. The loss of
transparency and the browning of the varnish had not only dulled the
colours but had also greatly reduced the sense of space and light within
the painting. The restoration has involved the gradual removal of the layers
of varnish and over-painting from what is often a remarkably thin paint
layer. There has been wide use made of brown glazes in this painting. In
many areas the paint is applied so thinly that the underlying light ground
can be seen through the brush-strokes. Fortunately the general condition
of the paint layer was good with few important losses. The restoration has
meant that we can now see Rubens’ painting clearly; we can appreciate
the different sources of light, the free handling of the paint and the
extraordinary sense of depth within the composition.
Technical study
The restoration process provides an ideal occasion to observe a painting at
close quarters and at the same time the opportunity to carry out technical
and scientific documentation. 1
The advantage of studying the technique of a recently restored painting
is being able to see the paint layer rather than trying to imagine it, hidden
under layers of dark and obscuring varnish. In the case of The Prodigal
Son, the technique proved to be a great deal more spontaneous and the
execution more rapid than it was thought to be prior to restoration. 2
Technique
a. The support
The Prodigal Son was painted on a well-constructed oak panel which
measures 109.75 x 158.2 cm. It is composed of 5 horizontal planks which
are butt-joined (ill. 1).
1. 22 - 23 cm
2. 22 cm
3. 20.75 cm
4. 24.75 cm
5. 20.50 cm
Ill.1 The dimensions and position of the planks, recto side.
All the planks are quarter-sawn; the fourth plank is partly false quartersawn,
where the medullary rays cross the annual rings diagonally. The
wood came from the Baltic region and planks 2, 3 and 5 are from the same
tree. Dendrochronology has been able to give an earliest felling date of
1613 for the fourth plank, giving the earliest possible creation date as 1615.
However allowing a 15-year average for sap wood rings, the more probable
date would be later, from 1621 onwards. 3

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Information about the construction
of the panel is limited by the
presence of a cradle (ill. 2) and a
double layer of lead white paint
applied between the elements of
the cradle in1895. 4
The panel must have been planeddown
in order to attach the cradle.
Under the vertical battens, we
can see that areas of the panel
were built-up by pieces of oak of
approximately 4
x 12 cm, glued side by side, presumably to
create a level surface for attaching the fixed
horizontal elements of the cradle (ill. 3). 5
Ill.2 The cradle on the reverse of the panel
The panel has been reduced in size on all
four sides but the presence of the vertical
prepared but unpainted edges on the recto
side, tells us that the amount may be slight as
the painting proper is intact.
The “unpainted edges” or margins correspond
approximately to a rebate of between 3 -7
mm, cut at a right-angle into the vertical
edges on the reverse of the panel (ill. 4). This appears
to be part of the original construction. We had thought
that the rebates were related to the framing but it now
seems probable that they were made to accommodate
temporary grooved battens, or ‘channel edge supports’
that were slid onto the end-grain edges of panels to
prevent warping. 6 A similar rebate can be found on the
reverse of the panel of “Christ and the Woman taken in
Adultery” by Rubens in the Musée Royal des Beaux-
Arts, Brussels. 7 The ‘unpainted’ edges of The Prodigal
Son have a ground layer (unlike the Brussels panel).
Ill.3 Detail of where a vertical batten of the
cradle has been removed to show that the
back of the panel had been built up before the
cradle was attached.
It seems that ‘channel edge supports’ may have been put on in the studio,
during the painting process, presumably when the panel began to warp.
This could explain why some paint can be found on the unpainted edge
but a distinct margin, or limit to the paint layer, was made once the battens
were in place.
b. The frame
We have no information about the original frame. The frame in which that
The Prodigal Son is currently shown is of English origin, dating from the
19 th century.
c. The ground
The panel was prepared with what looks like the traditional chalk glue
ground (ill. 5). It is off-white, thinly applied and is smooth and hard. Very
few samples were taken and in the cross-section (ill. 8) the ground appears
to be absent.
The ground continues to the edge of
the panel where the sharpness of the
outline confirms that the panel has
been trimmed. The “unpainted” but
prepared edges of the vertical sides of
the panel were obviously intended to
be covered later by the frame.
No isolation layer was visible. Because
much of the paint layer was thinly
applied, the white ground influences
Ill.5 Detail of the “unpainted” edge or margin.
The white ground can be seen where the frame has
rubbed away the overlying paint layers
the final painting by allowing light to
reflect through even the darker areas,
adding luminosity and transparency.
Ill.4 Detail of rebate along the vertical edge

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d. The imprimatura
A pale grey stripey imprimatura is present but not easily detected. Stripey
imprimatura is characteristic of Rubens panel paintings but it is most
commonly seen in his sketches on panel, such as the recently restored
Triumphal Chariot of Kalloo (KMSKA, inv. no 318),
where the imprimatura is ochre rather than grey.
It is often less apparent in his finished paintings, as
is the case here. It can be seen, however, in the gap
between the painted contours of the wooden post
and the sky and through the transparent brown
paint of the post (ill. 6). The imprimatura can be
seen more clearly with infrared photography (ill.
7) where it appears to have
been roughly applied with
a wide bristle brush in
horizontal and diagonal
directions (2.), changing
to a vertical direction
along the vertical edges.
Ill.6 The grey stripey imprimatura
can be seen in the gap in the paint
between the post and the sky.
Rubbed away the overlying paint
layers.
The stripey imprimatura may have acted as an
isolation layer preventing the oil of the paint layer
from sinking into the porous white ground. It
was also a device to give a tonality to the ground
without losing its luminosity.
Ill. 7 The grey stripey imprimatura
is visible under the transparent paint
layer of the tree and the wooden post.
e. The underdrawing
No underdrawing was visible or detected by infra-red photography. It is,
in any case, unusual to find underdrawing in Rubens’s finished paintings,
although more common in his sketches. An example, however, can be found
in The Farm at Laeken, (London, The Royal Collection), where “lines of
underdrawing are visible in the arm and face of the standing woman in the
centre” 8
f. The paint layer
Pigments
Analysis: a number of inorganic pigments have been identified by using
PXRF, a non-destructive method of analysis. 9 Organic pigments frequently
used by Rubens, such as red and yellow organic glazes, indigo, Cassel earth
and bitumen, cannot be identified by this method of analysis.
The following pigments were identified: white lead was identified in the
29 places that were analysed; sienna or possibly umber in the browns with
occasional traces of vermilion; vermilion probably in combination with red
earth for the reds; in the yellow highlights of the hay, lead-tin yellow with
probably a yellow earth. The greens were composed of a mixture of yellow,
probably lead tin yellow and a copper containing pigment, such as azurite,
or blue or green verditer. The blues used for clothing contained copper
indicating the use of azurite or blue verditer. However the blue for the sky
could be identified as either indigo or ultramarine / lapis lazuli. Very few
samples were taken from the paint layer. Two samples were taken from
the grey paint on the margin of the left edge. This was to identify the large
white grains that occur throughout the paint layer but predominantly in
the dark area of the roof, on the left side of the picture. Another sample was
taken in the sky to identify the blue pigment that could not be determined
by PXRF.
The ubiquitous white granular pigment was identified as lead white. The
sample taken to analyse the blue pigment in the sky can be seen in crosssection
(ill.8) where ultramarine/
lapis lazuli was identified. The
under-lying grey layer contains
chalk and lead white. Originally we
believed it to be the ground layer
but now see it as an intermediate
layer and that the ground layer is
missing. 10
Ill.8. Cross-section, taken from the sky with part of a leaf.
The blue pigment was identified as ultramarine / Lapis lazuli.
(Photograph, Antwerp University).

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g. Method of painting
One of the most remarkable aspects of the technique of this painting is the
apparent speed and spontaneity of its execution. The following description
is an attempt to describe the technique, by which way Rubens succeeded
in executing a complex, often thinly painted but detailed composition
while at the same time demonstrating an extraordinary liveliness in his
painting.
Establishing the composition:
It is difficult to know to what extent Rubens had developed the composition
for The Prodigal Son before transferring it to panel. In the absence of any
important changes of composition and the fact that areas were reserved
in the paint layer, we should conclude that it was carefully planned. The
composition, in any case, would have been underpinned by detailed
drawings taken from nature, such as his study of A Man Threshing beside
a Wagon, Farm Buildings Behind, ca 1617-18 (J.P. Getty Museum, Los
Angeles). In it we see an identical wagon in front of a similarly thatched
farm building. 11
There is no detectable underdrawing. One of the methods of transferring a
composition to its final support may have been with a material such as black
or other coloured chalk. The following
description may offer an explanation of
why we see no trace. “..it would seem from
the De Mayerne MS that it was customary
to erase, or nearly so, the initial rough
drawing in black chalk before or during
the painting process.” 12
If we look at Rubens’s sketches on panel, he
often used thin grey or warm brown paint
as a brushed drawing over the imprimatura.
This method allows alterations to be easily
adjusted while the composition is being
developed and does not disturb any final
transparent or thinly applied paint layer. Another method used by Rubens
to place figures was by painting into a scumble or opaque wet paint. 13 An
Ill.9 The cow’s horns have been provisionally
placed using thin brown fluid paint.
example of the former type of laying in or placing details in The Prodigal
Son, can be seen in the brown lines of the sow’s hind legs and, at a later
stage of the painting, where a cow’s horns have been provisionally placed
using thin brown fluid paint (ill.9).
While an example of the latter, wet paint method, can
be illustrated by the painting into the wet paint around
the woman feeding the pigs, where she was originally
placed more to the left and her shoulders have finally
been made less broad (ill.10).
Apart from the laying in of the structure of the barn
and principle elements of the composition, it would
have been important for Rubens to establish the areas
of light and shadow cast by the different sources of
light, daylight and candlelight. This would have to be
done in the early stages. The unusually
grainy texture of the paint surface that is
so noticeable on the left of the picture, in
the dark, thinly-painted rafters, is caused
by large grains of lead white pigment.
Ill.10 Painting into the opaque wet paint of the
background to place the woman feeding the
pigs. She was originally more to the left and had
broader shoulders.
They come from an underlying paint layer that may have been used to lay
in the composition. We do not yet know if the opaque grey paint visible
along the left vertical margin belongs to this laying-in stage but, if so, it
seems plausible that it was used to establish areas of light and shadow. (A
detail of the grey paint on the left margin can be seen in ill 5).
Ill.11 Infra-red photography gives a clear image
of the broad brush strokes and rapid execution of
the beams and rafters in the background.
The painting technique:
Once the composition was in place, the
painting of the background must have been
executed at great speed judging by the broad
brush strokes in the central rafters (ill.11),
and by the thin and transparent brown
washes applied along the beam that catches
the light (ill.12).
Ill.12 The beam was rapidly executed using
thinly applied transparent brown washes.

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By comparing a finished detail of the barn with an infrared photograph
of the same detail, we are able to see the spontaneous brush strokes that
underlie some of the final paint layer (ill.13, 14). The hurriedly-applied
dark horizontal brush stroke to the left, near the top edge of the panel,
crossing under the light-coloured roof supports, may have been intended
as another beam. The fact that it is now so
easily visible in the light areas underlines
the artist’s command of his technique
elsewhere in the painting.
As much as three-quarters of this
composition was painted using tones of
brown paint. Much of it was applied very
thinly and transparently as we can see
even in the dark areas of the roof. 14 The
middle and foreground are much lighter
in tone and in the immediate foreground
the paint is often so thinly applied that the white ground itself is barely
covered. An idea of how the painting stage developed can be seen by a
slight change of position in the skirt of the old woman holding a candle. 15
Ill.13 Detail of the barn in normal light
Originally she was painted advancing
further into the barn. A few highlights
corrected the position, but the firm linear
brush strokes of her original skirt remain
clearly visible (ill.15).
Ill.15 Shows, the firm linear brush strokes of an earlier
position of the old woman’s skirt ( just to the right)
Ill.14 Infra-red photograph showing detail of
the barn where the vigourous brush strokes of
the underlying paint layer are clearly visible.
The old woman’s head is an example of painting directly into the dark
background paint while it was still wet. It is also a remarkable example
of rapid and sure technique. By adding a few strokes of brown glaze and
white highlight he created her headdress and face. The whole is brought
to life by the dramatic red highlights under her chin and nose from the
reflected light cast up by her candle (ill.16). Elsewhere,
however, reserves in the paint layer were made to make
use of the lightness of the white ground and to some
extent, the effect of the stripey imprimatura. Examples
of reserves in the foreground include the two pigs on
the left, (but not the hind leg of the sow), the wooden
supporting post of the barn and the Prodigal Son’s head
and body. The tree trunk was reserved to the height of
the first fork, after which the branches were painted
over the blue sky. Even the belt of the bag hanging in
the centre of the picture, over the cows, was carefully
reserved. The blue sky was painted up to
either side of it, although the landscape had
already been sketched in behind (ill.17).
The belt is a device which, together with the
sight lines of the architecture of the barn, is intended to draw the onlooker’s
eye into the picture, through the barn and out to the countryside beyond. 16 .
The sense of depth was further enhanced by a glaze of natural ultramarine,
a vivid blue, added to the sky line just above the trees to the right of the
belt. The choice of ultramarine / lapis lazuli as the blue pigment for the
rest of the sky is interesting as it was very
expensive. Azurite, which tends to have a
greener tonality than natural ultramarine,
has been used as the blue pigment in the
rest of the painting. 17 Perhaps Rubens
decided that only natural ultramarine
could give the intense blue of day-light
that he needed to contrast with the
artificial and warmer candle-light in the
barn.
Ill.16 The old woman’s head was painted
into the wet paint of the background.
Ill.17 The belt was carefully reserved against the
sky. The blue paint was added to either side of it.

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Much of The Prodigal Son was executed alla prima. The rapid execution,
already noted in the broad-brush treatment of the background, can also be
illustrated by the numerous examples of painting wet paint into wet paint.
These include the cock’s tail painted with three rapid brush strokes into
the wet background paint (ill.18), working
into wet impasto paint with the stub-end of
the brush to imitate basket weave (ill.19),
painting a branch through the impasto paint
in the tree (ill.20) and the standing heifer’s
rump, where the wet paint of the short
diagonal brush strokes have been dabbed
with a brush leaving round textured marks
in the wet paint (ill. 21).
Ill.18 The cock’s tail was painted with three
rapid brush strokes into the wet background
paint.
Ill.21 The short diagonal
brush strokes have been
dabbed with the end
a brush making round
textured marks into the
wet paint
Ill.23 The white impasto paint of the
cock’s neck feathers, was applied with a
finely pointed brush.
Ill.26 By comparison the
hind legs have an almost
sketchy execution.
Of the many types of brush strokes that
are clearly visible in the paint layer, a few
examples are: in the thatch of the barn roof,
where the brush strokes can be seen in the
thinly applied, transparent paint (ill.22).
The cock’s neck feathers, (ill.23) where
white impasto paint has been applied with
rapid strokes of a finely pointed brush, and
the horizontal brush strokes in the barn,
where a more flat-ended brush was used (ill.24).
Rubens has employed an almost graphic way
of painting the cows and the pigs, where
the diagonal brush strokes are similar to a
hatching technique used in drawing. These
lines follow the form and create a sense of
volume using a minimum of material. The
two horses were painted using a similar
Ill.20 Painting a branch through the impasto
paint in the tree.
Ill.19 “Drawing” into the wet impasto
with the stub-end of the brush
to imitate the basket weave.
Ill.24 Horizontal brush
strokes, where a more flatended
brush was used.
Ill.22 Brush strokes are clearly visible in the thinly
applied paint of the thatch of the barn roof.
technique, but the areas of light and shade of the grey
stallion were given more substance by the addition of
a smooth and fluid paint layer, either of transparent
brown in the shadow or pale grey in the light areas. The
hindquarters seem to have been underpainted with a
dark grey paint applied in irregular circular patterns,
over which the lighter grey was added to produce a
subtle dappled effect. Highlights were added in short
diagonal strokes while white impasto paint completed
highlights to the tail.
Some parts of The Prodigal Son were painted with
attention to detail, particularly in the centre while in
areas that were less likely to be noticed the execution is
particularly free and almost sketchy. Thus the central

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heifer’s head is painted with a high degree of finish
(ill. 25) while her hind legs, in shadow, have a more
summary, almost sketchy execution (ill. 26).
This is a painting that can best be appreciated by standing
at some distance. As we have seen Rubens employed
a number of devices to enhance the element of space
within this composition. The final brush strokes may
well have been the rapidly applied highlights added
to the fork in the foreground and some of the more
hurriedly applied cobwebs in the rafters, again with the
idea of drawing us into this remarkable painting.
Susan Farnell
Ill.25 The central heifer’s
head is painted with a high
degree of finish.
Rubens is believed to have retouched The Prodigal Son later on in his life.
The painting was, in any case, in his possession at the time of his death.
Apparently the artist was unable to resist the temptation of making
adjustments to the composition. Unlike the other faces in the painting,
that of the stable hand on the far left is executed in very expressive, patchy
brushstrokes. This style does not correspond with the smooth, calligraphic
approach that is so characteristic of Rubens’s work from around 1618. The
white horse also appears to have been retouched. Its head, unlike the rest of
its body, was not kept in reserve, but sketched onto the brown background
colour in a few quick light brushstrokes. The hind end and tail have been
accentuated with some touches of white paint, so that the horse catches
more light and thereby draws the viewer’s attention. Also, Rubens added
some volume to the right flank of the brown horse. The purpose of these
corrections was possibly to achieve a better balance in the composition.
Without the alterations, clearly the most illuminated areas in the picture
were on the right-hand side.
In the print after the painting by Schelte Adamsz Bolswert, one notices
that the large deciduous tree in the farmyard was originally a rather measly
pollard willow. We were able to determine by means of an infrared image
that Rubens reserved the shape of this pollard willow in the paint layer, as
we notice the stripy imprimatura through the thinly applied paint of the
trunk (ill. 7). This is however not the case for the rest of the trunk and the
branches, which were painted over the greyish-blue sky. Perhaps Rubens
chose to add a lush crown to soften the transition from the bright sky
to the angular contours of the barn. Rubens is known to have retouched
other paintings which he felt no longer tied in with his artistic aims. In
quite a few cases, such corrections involved adjustments and sometimes
enlargements of the support. 18
There are hardly any other paintings of this size in Rubens’s oeuvre that have
been painted as sketchily as The Prodigal Son. The explanation probably
lies in the fact that the barn, which takes up most of the composition, is
shrouded in twilight, and Rubens tended to provide far less detail in the
darker areas of his paintings than in the brighter ones. The only comparable
“cabinet picture” is The Calydonian Boar Hunt in Los Angeles (c. 1611), 19
in which the boar as well as the foreground and background are also
rendered rather sketchily. There are however a
number altarpieces, including the Adoration of
the Magi in Antwerp (1624), the St. Ildefonso
Triptych in Vienna (1630-31) and the Adoration
of the Magi in Cambridge (1633-34), which
were executed with similar economy of means.
The same holds for the monumental Hercules
Drunk in Dresden (1613-14). 20 Rubens executed
these large paintings himself, quickly, alla
prima, with medium-rich paints that he could
apply thinly to the panels. As a consequence,
the chalk glue ground is visible through the
paint layer in many places in these works. As
in The Prodigal Son, individual brushstrokes
in the abovementioned paintings are visible
Ill. 7 The grey stripey imprimatura is visible under the
transparent paint layer of the tree and the wooden post.

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mostly in the shaded areas. The technique of scratching into wet paint
with the back of a brush, which Rubens applied in the basketwork in The
Prodigal Son, is rather rare in his oeuvre (unlike in the work of Rembrandt,
Jan Lievens, Aert van der Neer and Arent de Gelder). 21
Nico Van Hout
1) The following documentation was carried out:
Dendrochronology, see note 3.
Infra-red Photography, (Adri Verburg).
Infra-red Photography with false colour, (Adri Verburg).
UV photography (Susan Farnell).
Photographic documentation (Susan Farnell and Adri Verburg).
Non-destructive inorganic pigment analysis (PXRF), see note 9.
Cross-sections and analysis, see note 10.
X radiographs were not taken because of the lead white on the reverse of the panel
2) John.Smith, Catalogue Raisonné, 11, 804; 1X, p.300, N° 205. “ …the picture is painted with extreme
care..”
3) P. Klein (Zentrum Holzwirtschaft an der Universität Hamburg), Report on the
dendrochronological analysis of the panel, 17.3.2005.
4) Archives of the KMSKA. The painting was acquired for the Museum in 1894, bought from
Gauchez, Paris. The earliest treatment report that was found in the archives dates from 14 th March
1895. It is a proposition by Maillard to re-glue the panel, to make a cradle and apply a double layer of
ceruse to the back of the panel. (Archive dossier E 18f ). 1895 Maillard Archief, box E6,E8d, E8e. 1896
Maillard Archief, E8e. E18f 1937 No information, just reference. 1946 C. Bender, information, nothing
specific. 1953 Just reference. 1977 Just reference. Also mentioned in two reports of Benders in 1994
and 1996.
5) J.A. Glatigny, The support was treated in 2004. The sliding elements of the cradle needed to be
unblocked prior to restoration, to prevent strain on the panel. The two horizontal breaks in the panel
and all but one of the numerous short splits along the vertical edges were stable.
6) In many cases the ‘channel edge supports’ would have been in place before the ground was applied
to the panel and only removed once the painting was to be framed; in that case the panel would have
two unpainted and ungrounded edges and a ‘barbe’. I am grateful to Christina Currie for information
concerning ‘channel edge supports’. For more detailed information on this subject see D. Allart et
C. Currie, ‘Analysis of selected works by Pieter Bruegel the Elder and Pieter Brueghel the Younger’,
Brussels, Royal Institute of Cultural Heritage, collection Scientia artis (forthcoming).
7) This work was also painted on a panel constructed with horizontal planks. The recto side has two
ungrounded-edges and a “barbe” indicating that the ground was applied when the vertical sides
were held in ‘channel edge supports’. These must have been removed during painting as the paint
layer overlaps the “barbe” onto the wood of the unpainted-edge. I am grateful to Hélène Dubois for
this information; detailed information gathered during the Rubens Project of the Musées Royaux
des Beaux-Arts de Belgique in Brussels, should be available at the end of next year, probably as a
database/web site.
8) C. Brown, Making and Meaning: Rubens’s Landscapes, exh. cat., London, 1996, p. 117.
9) Pigment analysis, using PXRF (Keymaster Tracer III-V), was carried out by Geert van der Snickt
and Koen Janssens, Antwerp University, department of Chemistry. The identification of inorganic
pigments by this method is made by a process of deduction: in this case, by comparing the chemical
elements present in a sample of approx. ½ cm² with those of a comparable colour, from the limited
number of pigments available to artists in the 17 th century. Secondary colours such as green could be
of a single mineral origin but were often made of mixtures of blue and yellow thus complicating the
identification of the pigments used. XRF identifies elements through the depth of the paint layer and
beyond, not just on the surface, which may lead to results that are difficult to interpret.
10) Koen Janssens, G. van der Snickt, cited note 9, Cross-section and SEM and analysis by XRD.
11) See also Study of an Ox, ca. 1618, Albertina, Vienna (8253); the central heifer in the Prodigal Son is
very similar to this study but in reverse position. A similar ox appears in The Farm at Laeken, London,
The Royal Collection, (RCIN 405333). In the same painting the position of the cow that is lying-down

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is close to one in The Prodigal Son, but in reverse, as is the man on horse back, leading another horse
to water.
12) J.Plesters, ‘“Samson and Delilah”: Rubens and the Art and Craft of Painting on Panel’, National
Gallery Technical Bulletin 7, 1983 p 38, note 21.)
13) Both these methods can be seen in his sketch of the Triumphal Chariot of Kalloo, Koninklijk
Museum voor Schone Kunsten, Antwerp, inv. no 318.
14) However in some areas where dark brown or black paint was applied more thickly, premature
drying cracks can be seen in the paint layer. This problem occurs in other paintings by Rubens and
may be due to a bituminous content in the paint. See R. White, ‘Brown or Black Organic Glazes,
Pigments and Paints’, National Gallery Technical Bulletin, 10, 1986, pp 58-71, p. 62, for problems
caused by bitumen and aspheltum in the drying of oil film, and p.65, lignites and peats as principle
source of Cologne earth, retards drying in oil films. J. Kirby, ‘The Painter’s Trade in the Seventeenth
Century: Theory and Practice’, National Gallery Technical Bulletin, 20, 1999, p.38 on Cassel or Cologne
earth, and other dark brown translucent pigments used by Rubens and Van Dyke; in same volume R.
White, ‘Van Dyke’s Paint Medium’, pp. 84-88, esp. p. 84 with reference to paint film defects and also
brown-black tars, pitches and bistre.
15) A slight change of position can be seen in infrared photography where the winnowing fan,
hanging on the wall, seems to have been smaller. There is a deformation in the panel near the top
of the basket. We cannot be sure whether this is an old area of damage or perhaps an original repair
in the panel. We are also not sure of the reason for losses in the paint layer of the skirt of the young
woman feeding the pigs. Before restoration, they were thought to be due to flaking paint. This proved
not to be the case but the paint has been damaged in localised areas.
16) The perspective has been slightly corrected in the engraving of The Prodigal Son by Schelte à
Bolswert (reproduced in M. Rooses, L’Oeuvre de P.P. Rubens, Antwerp 1888, vol. 11, pl. 89). There are
a number of other variations, some of which include: the cows being carefully tethered, one of the
mare’s forelegs is visible, the winnowing fan on the wall is smaller; the main tree is pollarded. The
engraver has misunderstood the construction of the roof in the top corner above the manger, where a
diagonal roof support has become a rafter.
17) Kirby 1999, cited in note 12, pp 35-36.
18) Cf. G. Martin, ‘Two closely related landscapes by Rubens’, in The Burlington Magazine, 757,
CVIII (April 1966) pp. 180-184; R. Bruce-Gordon, ‘Rubens’s “Landscape by Moonlight”: technical
examination, in The Burlington Magazine, CXXX (August 1988), pp. 591-596; V. Poll-Frommel, K.
Renger, J. Schmidt, ‘Untersuchungen an Rubens-Bildern: Die Anstückungen der Holztafeln’, in
Jahresbericht Bayerische Staatsgemäldesammlungen, 1993, pp. 24-35; K. Renger, ‘Anstückungen bei
Rubens’, in Die Malerei Antwerpens: Gattungen - Meister -Wirkungen (Vienna, 1993), pp. 157-160;
K. Renger, ‘Rubens-stücke. Die Anstückungen von Münchner “Silen” und “Schäferszene”’ Wallraf-
Richartz-Jahrbuch, LV, Festschrift für Prof. Dr. Justus Müller Hofstede (Cologne, 1994), pp. 171-184;
N. Van Hout, ‘A second self-portrait in Rubens’s “Four Philosophers”, in The Burlington Magazine,
CXLII, 2000, pp. 694-697.
19) Calydonian Boar Hunt, Los Angeles, The J.P. Getty Museum, inv. no. 2006.4.
20) Adoration of the Magi, KMSKA, inv. nr. 298 (Jaffe 1980, no. 780); St. Ildefonso Triptych, Vienna,
Kunsthistorisches Museum, inv. 678/ 698 (Jaffé 1980, no. 998); Adoration of the Magi, Cambridge,
King’s College Chapel (Jaffé 1980, no. 1095); Hercules Drunk, Dresden, Gemäldegalerie Alte Meister,
inv. no. 987 (Jaffé 1980, no. 215).
21) See also Rubens’s St George Slaying the Dragon (Madrid, Prado, inv. no. 1644; Jaffé 1980, no.
69). Here, the hairs of the horse’s tail are also scratched into the dark paint. As a result, the beige
underpainting comes to the surface.