Reconstructing Rogier : Practical Insights into the Original Appearance of the Lamentation Attributed to Rogier van der Weyden, Based on Student Reconstructions

Introduction

Educational programmes that train paintings conservators or technical art historians often involve students in making reconstructions of artworks.¹ At the University of Amsterdam, students from the Technical Art History master’s programme learn about the process of making and the stratigraphy of historical paintings, as well as the interpretation of technical data, by attempting to make a faithful copy of a painting using historically appropriate materials and techniques. In 2020, students based their reconstructions on the Lamentation of Christ (ca. 1460–64) attributed to Rogier van der Weyden, which is the oldest painting in the collection of the Mauritshuis, The Hague, in the Netherlands (Fig. 1).² In 2018–19, this artwork underwent a thorough technical examination using advanced scientific technologies, as well as conservation and restoration treatment, in front of the public.³ The results from this research were an excellent basis for the student reconstructions and led to discoveries about the materials and techniques that were used to make the painting.

The panel (80.6 X 130.1 cm) was made from six vertical planks of oak, prepared with a chalk-glue ground, probably applied with a brush. The underdrawing was executed in at least three phases (and possibly by different hands), employing both dry and fluid materials.⁴ An intermediate layer, applied thinly on top of the underdrawing, is a slightly warm pinkish colour. The composition of the paint layers is in keeping with the palette usually employed by Rogier van der Weyden and his workshop.⁵ The colours used to differentiate the clothing of eleven different figures are bright and saturated, generally created by using opaque underlayers superimposed with translucent glazes. The visual effect of some of these glazes – to impart modelling and colour intensity – has been affected by fading in response to light.⁶ Although in some cases it was difficult to determine the extent of fading, comparing exposed areas of paint to those that had been covered by old retouchings and fills gave an indication of colour change.

Despite the wealth of technical information provided by scientific analysis and imaging, some questions remained, specifically: the functions of layers beneath the surface, the original appearance of certain coloured fabrics and how they might have changed over the centuries, and the working process of the artist to create shiny, reflective details. Previous studies have demonstrated how reconstructions made with historically appropriate materials can be used to investigate the original appearance of artworks.⁷ Such reconstructions also allow a practical perspective on the making process that may support the interpretation of analytical data and help to substantiate suggested relations to art-technological sources.⁸ A 2012 article by Marie Postec describes how painted reconstructions made by students helped to answer questions specific to Rogier van der Weyden’s Seven Sacraments Altarpiece (ca. 1445–50, Koninklijk Museum voor Schone Kunsten, Antwerp).⁹ The recent research into the Lamentation involved a similar approach but focused on different questions.

By making reconstructions of specific areas of the Lamentation, the students could experience every step in the production process of a painting: from the making of raw materials to the joining of planks and the application of ground layers, to the preparation and application of paints containing a variety of pigments and processed linseed oils. They were able to appreciate the bright colours of un-aged paints, which provided them with a reference to assess the degree of ageing and discolouration in historical paintings. They also developed their skills in interpreting the scientific data that they used as a basis for their reconstructions, and learned to design their experiments in a way that would answer specific research questions. Thus, they learned to appreciate the values and limitations of reconstructions as a research method in technical art history. Whilst most educational programmes would not necessarily expect student reconstructions to solve any particular questions about the original artwork, in this case the exercise was seen as a chance to complement the technical study of Van der Weyden’s Lamentation. In their reconstructions, the students were encouraged to evaluate rationales behind the choice of materials and techniques, and to investigate some hypotheses that were brought forth by the conservators who carried out the treatment of the original painting.

That said, there are some obvious limitations to this approach. While a fifteenth-century Netherlandish artist would have been trained over several years as an apprentice in a master’s workshop, these modern-day students had little prior experience with making reconstructions as part of a course in interpreting art historical sources. This meant that they quickly gained a lot of tacit knowledge, including the affordances and properties of various materials and the way they can be used to create certain effects while working. Such a learning-by-doing approach means that the students inevitably made some – often quite insightful – mistakes, and may have experienced difficulties that professional artists would not have. Moreover, in some cases concessions had to be made regarding the historical appropriateness of materials and tools due to safety regulations and practical limitations. Despite our efforts, it is never possible to truly replicate a historical process in all its peculiarities, and it has not always been possible to prove that an effect observed in one of the reconstructions necessarily accounts for a similar effect in Van der Weyden’s Lamentation. However, performing technical analysis on the reconstructions and comparing the results with those from the original artwork provides both students and readers with an opportunity to gain deeper insight – not only into the quality of the reconstructions – but also into the interpretation of the historical painting. Therefore, we would like to propose that technical research into reconstructions become a more common part of reconstruction-based research, as well as education.

Reconstructions

As part of the course “Historical Reconstructions,” selected areas of the Lamentation were reconstructed by second-year students of the Technical Art History master’s programme in the Conservation and Restoration Department of the University of Amsterdam.¹⁰ Two paintings conservators who had participated in the treatment of Van der Weyden’s Lamentation at the Mauritshuis (authors Pottasch and Vandivere) made reconstructions alongside the students. The course was supervised and coordinated by the third author (Kneepkens).

Before the reconstruction process began, the conservators gave a presentation about the history and technical features of the Lamentation. Each student selected an area of the Lamentation (approximately 12 X 12 cm), conceived of appropriate research questions, and thought about how to organise their reconstruction to address their questions. Students were provided with digital and printed technical images of the painting, including: X-radiographs, macro-X-ray fluorescence scans (MA-XRF), infrared reflectograms, and photographs taken at different stages of the conservation treatment.

Each student joined two oak planks, sized the panel, and applied and sanded a chalk-glue ground.¹¹ The next phase was the application of the underdrawing, using the infrared reflectogram as a guide (see Question 1 below). On top of this underdrawing, they applied a thin pinkish-grey intermediate layer (see Question 2). The students continued painting their selected area based on the technical information provided. “Historically appropriate” pigments and materials were selected when possible, but for reasons of safety and time limitations some substitutions had to be made (see Table 1).¹² Naturally, the materials and stratigraphies of the reconstructions varied somewhat based on the research questions and the choices made by each student. Within their 12 X 12–cm squares, some parts were “finished,” and others were left intentionally incomplete or incorporated materials or techniques that differed slightly from those used in the original painting. Each student kept a logbook documenting their steps and observations and photographed their reconstructions at different stages. Through the process of exploration and reconstruction, new questions and observations arose that generated discussions amongst the group. Five questions were selected for this article, based on different parts of the painting’s layer structure.

Research Questions

1. What does the appearance of the underdrawing in the reconstructions tell us about the preparatory phases of Van der Weyden’s Lamentation?

The underdrawing of Van der Weyden’s Lamentation has been detected using various infrared cameras.¹³ Differences in the width and intensity of the lines suggest that the underdrawing was applied in at least three phases, possibly using different materials and tools, and/or drawn by different hands.¹⁴ For example, at an early phase some contours and guidelines were applied with a dry material (black chalk). In the Virgin Mary’s blue cloak (Fig. 2a), the folds were indicated by broad dark lines applied with a black liquid medium and a brush or quill, whereas the shadows were indicated with fine hatching, also likely applied with a liquid medium (Fig. 2b).¹⁵ Some compositional changes between drawing and painting phases (pentimenti) were detected: for instance, a shift in the position of Christ’s hand.

In their reconstructions, the students tried different methods to apply their underdrawings. After tracing the infrared reflectogram using a dry material, they chose a fine brush, a feather quill, or both to apply an aqueous black ink, and tried to emulate the thick and fine lines that were detected in Van der Weyden’s painting.¹⁶ The brush was good at achieving dark pointed lines that resembled the broader underdrawing of the Lamentation. Several participants mentioned that a homemade quill was easier to use, perhaps because it felt more like a modern pen. They observed that it was possible to draw in all directions by slightly adjusting the angle of the quill, and the thickness of line was easier to control than with a brush. Therefore, the quill was found to be particularly suitable for the finer lines. Also, it held ink better than a pen and did not require repeated dipping into the inkpot.

To assess which tool created lines that were most similar to those applied by Van der Weyden, the reconstructions were examined using an Osiris camera: one of the same infrared reflectography cameras that had been used to examine his Lamentation. In most reconstructions, the visual effect of the combination of fine and thick lines appears very similar to the original. The student who reconstructed the area around the Virgin Mary’s blue cloak primarily used a quill to apply the underdrawing: both the dark broad contours (for the folds) and the thin hatched lines to indicate the shadows (Fig. 2d).¹⁷ One difference is that in the original painting the broad lines appear more pronounced and sometimes have a “puddle” at the end; they might actually have been applied with a brush. Already after the application of the first layer of paint (containing azurite and lead white), the underdrawing became difficult to follow because the paint was rather opaque (Fig. 2c). In contrast, several other students remarked that it was sometimes difficult to cover the darkest lines at the painting stage. This was especially true where the paint was relatively translucent, or where pentimenti were present.

In Van der Weyden’s Lamentation, the underdrawing was adjusted during different phases, and also the artist changed some of the outlines during painting; however, it is remarkable that pentimenti are rarely visible with the naked eye, apart from a few places in the flesh tones and where the paint is thinnest.¹⁸ Although this remains hard to prove, we may be able to conclude that Van der Weyden was aware of the degree to which the underdrawing would eventually be visible through the paint layers. From a practical perspective, it seems plausible that he might have varied the intensity of his lines, perhaps anticipating the specific mixtures that would be used on top, including eventual intermediate layers.

2. In the flesh tones and light-coloured areas, what is the role of the intermediate layer?

In most cross-sections from Van der Weyden’s Lamentation, a thin layer (less than 10µm thick) lies between the underdrawing and the paint layers (see Fig. 7b). It contains lead white, red earth, and a very fine black pigment. In historical sources and literature, such a layer is referred to as an isolation layer, tinted priming, or primuersel.¹⁹ Similar layers have been identified in other works from Van der Weyden’s oeuvre, including the Seven Sacraments Altar.²⁰ Its presence may have fulfilled several functions, including: preventing the underdrawing from smudging when paint layers were brushed on top, muting the dark colour of underdrawing, preventing the binding medium of the paint layers from being unevenly absorbed into the ground, and acting as a base tone.²¹

All students applied the same paint as an intermediate layer to (parts of) their reconstructions, made with pigments mixed with linseed oil that had been sun thickened in a lead container.²² Once it was dry, the layer had a rather rubbery surface that gave some resistance when it was wiped with a finger. During painting, the layer had different characteristics across the various reconstructions, depending on the thickness of application and the smoothness of the ground layers beneath. On the smoothest panel, the layer seemed the most rubbery; as a result, during application of the subsequent paint layers, the coarse pigments did not always stay in place as they were being brushed on top. In other panels where the ground layer was rougher or uneven, this smoothness was an asset during painting.

One participant reconstructed the area around Christ’s body and applied the intermediate layer over the underdrawing (charcoal bound in gum arabic, applied with a brush) on the left part of the panel only (Fig. 3b). She then observed whether there were differences when flesh-coloured paints and the white paint of the loincloth were applied on top of the surfaces (Fig. 3c). The four aforementioned functions of the intermediate layer were assessed. It prevented the underdrawing from smudging when paint layers were applied, but even without such a layer, the smudging of underdrawing was not a major problem. Both the light and dark lines of underdrawing remained visible and easy to follow at the paint stage; however, the intermediate layer muted the darkest lines of the underdrawing, which was important in minimizing the visibility of pentimenti. Comparison of cross-sections taken from the primed and unprimed parts of the composition showed that the intermediate layer did indeed prevent oil from the paint layers from being absorbed into the ground.²³ Although when it was first applied, the layer was perceived as having a somewhat dull and pale colour, the intermediate layer was an effective base tone. Its greyish-pink colour helped to give Christ’s dead flesh a convincing tone, especially where the paint was thinly applied; however, in the completed reconstruction, there is barely any colour difference between the flesh applied on top of the primed and unprimed areas (Fig. 3d).

The function of this layer as a base tone is likely one of the reasons why some early Netherlandish painters seemed to have adopted flesh-coloured intermediate layers, especially for portraits or compositions with many figures.²⁴ It made the painting process more efficient because fewer or thinner paint layers needed to be subsequently applied to give a convincing impression of skin. Visually, its colour encompasses both the cool and warm tones of real flesh. Most parts of Van der Weyden’s Lamentation are rather thickly painted with bright colours.²⁵ Although the colour of the intermediate layer might have helped to make the process more efficient in the skin tones of the eleven figures, the rest of the painting barely benefits from its visual effect. Perhaps its main functions were to prevent the medium from soaking into the ground layer, to tone down or even out visual differences in the underdrawing, to efficiently build up certain colours, and/or to provide a smooth surface on which to apply and blend the paint.

3. What was the original appearance of coloured draperies in the Lamentation?

The following sections investigate the buildup and original appearance of various draperies from Van der Weyden’s Lamentation, some of which seem to have been affected by chemical and physical changes over time. The pigments identified using MA-XRF and examination of cross-sections were similar to the pigments found in previous studies on paintings by Van der Weyden, including the Boston Saint Luke Drawing the Virgin (ca. 1435–40), the Uffizi Entombment (ca. 1460–63), and paintings from the National Gallery, London.²⁶

3a. Blue draperies

Van der Weyden’s Lamentation features several blue draperies that originally had slightly different tones. Each of them seems to have changed over the course of time, but in different ways. The dress worn by the standing woman on the left (Mary Magdalene) is very dark – almost black – and appears to have little modelling (Fig. 4a). There is almost no definition between highlights, mid-tones, and shadows, and her upper arm seems to have merged into her bodice. Cross-sections reveal that the dress consists of a layer of very coarse azurite (a relatively opaque and inexpensive blue pigment), followed by a glaze of fine ultramarine (a more translucent and precious blue pigment) (Figs. 4c, 4d).

Based on this information, one student investigated the original modelling of Mary Magdalene’s dress by testing three different approaches (Fig. 4b).²⁷ In the bodice, he first applied a thin, unmodelled layer of pure azurite, then achieved the modelling in the upper ultramarine layer. In the sleeve, he attempted to differentiate the folds by adjusting the thickness of the azurite underlayer, then applied a relatively even layer of ultramarine on top. In the lower part of the dress, he also applied modelling in the azurite underlayer, both by varying its thickness and by producing highlights by mixing the azurite with lead white. When he compared his reconstruction with details from Van der Weyden’s Lamentation, the student was most convinced by the approach chosen for the sleeve.²⁸ It should, however, be noted that cross-sections from the original and reconstruction had different layer thicknesses; the ultramarine layer that Van der Weyden applied was thinner than the one in the reconstruction (Figs. 4c, 4d). Whilst the student had a clear preference, this may have been influenced by his lack of experience. The extreme darkening of this section in the original artwork makes it hard to draw a sound conclusion; however, the reconstruction does give an idea of the original contrast, now lost, between the blue and red draperies.

A similar experiment was conducted by another student, who tried three approaches to paint the dress of the Virgin Mary (Fig. 2c). In Van der Weyden’s Lamentation, this garment may also have lost some of its modelling, although its overall colour is still rather blue, and some folds have remained visible. The student concluded that mixing the azurite with lead white was the most successful way to achieve convincing midtones and highlights in the Virgin’s dress. Modelling the garment by only varying the thickness of the azurite paint was especially difficult because the large pigment particles slid around on the intermediate layer. Trying to achieve differences in tone with only ultramarine was difficult because it was too translucent to provide a convincing suggestion of depth and shadow.

Cross-sections from Van der Weyden’s Lamentation show that the Virgin Mary’s dress was also painted with azurite, followed by a glaze containing exceptionally large particles of ultramarine. The MA-XRF scans indicate that one or both paint layers also contain lead white. This may have helped provide the heightened impression of highlights and midtones, and could explain why this garment retained its modelling better over time as compared to Mary Magdalene’s dress (described above), where much less lead white was incorporated into the paint. Unfortunately, the glazes in the Virgin Mary’s dress – especially in the darkest shadows – have been affected by “ultramarine sickness.” The particles scatter the light, causing surface blanching and thereby diminishing the contrast between the lighter and darker areas.²⁹

The third “blue” drapery studied was the light-coloured dress of the Seated Mary at the lower left (Fig. 5a). A significant part of the skirt had become severely damaged by the heat from candles. The original paint had burnt or flaked off, and the damaged area was overpainted in the sixteenth or seventeenth century.³⁰ During the recent conservation treatment, it was found that the old overpaint covered parts of the original paint and had locally protected it from exposure to light. The protected areas were more purple or pinkish in tone than the rest of the skirt. The presence of white, blue, and red pigments – as well as the areas that were protected by the overpaints – suggest that the dress worn by the Seated Mary originally had a somewhat more purplish appearance.

One student wondered how the presence of red lake originally affected the colour of the paint mixture. She incorporated several types of lakes into her reconstruction, including madder lakes she made based on historical recipes, and commercially available pigments (Fig. 5b).³¹ During the reconstruction it became clear that the specific colour of the red lake had a profound impact on the mixture; while a slightly brownish madder lake rendered a greyish-brown paint, a more bluish madder resulted in a pale violet that was closer to the present appearance of the dress. Although it was impossible to determine the precise colour of the original paint, and therefore the extent of fading, it did become clear that even a little amount of the correct red lake turns the paint from light blue to purple.

A comparison of cross-sections from shadow areas in the original skirt and reconstruction showed similarities in the type and size of pigment particles; in the original, however, finer pigments are in the lower layers, whereas in the reconstruction they are in the upper layers (Figs. 5c, 5d). A comparison of the uppermost paint layers suggests that the reconstruction could have been more comparable if additional blue and red pigments had been incorporated, which would have resulted in an even darker drapery. Despite this difference, the few particles of red lake that were observed in the paint sample and under the microscope indeed suggest that the dress of the Seated Mary was originally more violet or purple in colour.

3b. What was the original appearance of the clothing worn by the Standing Mary?

We also had questions about the original appearance of the clothes worn by the Standing Mary (second figure from the left) (Fig. 6a). Her brown gown is lined with fur, and the fabric itself appears heavy due to its crisp folds. Underneath she wears an orange kirtle, which seems to be made of a lighter fabric with looping folds. Such a colour combination might seem unusual for clothing worn by a Biblical figure or by a wealthy person in the fifteenth century (that is, contemporary to Rogier van der Weyden). So far, no clothing with this specific colour combination has been found in other works from his oeuvre or by other fifteenth-century artists.

MA-XRF scans of the brown gown in Van der Weyden’s Lamentation reveal that it contains mercury (Hg), lead (Pb), and potassium (K), respectively corresponding to the pigments vermilion, lead white, and probably the substrate for a lake pigment. Examination with a 3-D digital microscope shows that the paint mixture in an underlayer contained a black pigment in addition to red and white particles. The surface layer with a finer crack pattern is likely a faded layer of red lake glaze. A reconstruction tested whether this combination of pigments would result in a brown colour, or perhaps more purple (Fig. 6c).³² A paint layer containing vermilion, lead white, and carbon black was applied, followed by a thin, even layer of madder lake precipitated on a potash-alum substrate. The resulting colour was a dark reddish-brown. Presumably, choosing a different type or shade of the red lake (see Question 3a) would have resulted in slightly different tones for the garment.³³

The kirtle that the Standing Mary wears underneath the gown is an opaque orange colour. Microscopic examination suggests that the top layer contains red lake, which has since faded. A cross-section from her skirt confirms that the paint is built up in three layers, the topmost of which includes both pink and colourless particles at the surface, indicating a faded red glaze (Fig. 6d). This suggests the orange kirtle would have had a redder hue when it was first painted. The highlights in the sleeves – where the glaze is thin or absent – would likely have contrasted with the intensely coloured mid-tones and shadows, creating a more convincing modelling.

A cross-section was taken from a shadow in the sleeve of the reconstruction of the Standing Mary (Fig. 6d). Although the samples were taken from different parts of the garment, the sample from the orange skirt in Van der Weyden’s painting and the thickness of the upper paint layer in the reconstruction (Fig. 6e) are similar. In ultraviolet (UV) illumination, both cross-sections show strongly fluorescing red lake particles; however, in the reconstruction the drying time between painting sessions was not long enough, so the red lake paint has blended with the layers beneath. The type(s) of red lake used in the original and reconstruction might not have been identical,³⁴ but the effect of a red lake glaze shows that it imparts extra colour intensity and saturation.

3c. What was the original appearance of the red fabrics?

Different shades of red draperies are found throughout the Lamentation, and some appear to have changed more than others. The red lake used to depict the velvet of the bishop’s cloak (at lower right in Fig. 1) seems to have retained the intensity of its deep crimson colour. In comparison, in the clothing of Mary Magdalene (standing at far left), Saint John (center), and Saint Peter (far right), the red lake glazes applied as a final layer to impart midtones and shadows have faded. The more noticeable effect of fading due to light exposure may have been the result of the thinner application of glazes and/or abrasion during restoration treatments. The underlayers in the clothing of Mary Magdalene and Saint John also contain lead white, which could have additionally contributed to internal light scattering and fading.³⁵

In Saint Peter’s red cloak, the mid-tones and shadows have become faded and/or abraded, which affects its three-dimensional effect (Fig. 7a).³⁶ A cross-section from a shadow in the cloak shows that Van der Weyden laid in the underpaint with vermilion mixed with red lake (Fig. 7b). He then achieved the modelling by applying several layers of glazes, each containing progressively more red lake. The student who reconstructed this area noted that vermilion is very opaque and consequently tended to cover the underdrawing before proper modelling was achieved (Fig. 7d). She found that incorporating red lake in the underpaint was an effective way to create shadows. Finally, she applied the darkest shadow with a pure red lake glaze, in this case, an insect-based lake made from the secretions of Coccus Lacta.³⁷ This stratigraphy can be seen in a cross-section from the reconstruction (Fig. 7c). Although initially the bright orange-red underlayer and translucent red glaze seemed quite close to the colours that we presumed to have been used by Van der Weyden, a surprising effect was noted once the reconstructions had been displayed for several months in the conservation studio. After approximately three to four months, the red lake glaze began to darken and turn more purplish (Fig. 7e). The reason for this colour shift is unclear, but it was observed in all of the reconstructions that incorporated this pigment. As most red lakes eventually fade in response to light, one expects that over a longer term this and other red paints will change colour again.

Previous studies of paintings from the Van der Weyden group have suggested that several types of red lakes were used – including madder and insect-based lakes (probably kermes) – but have also acknowledged that identifying these materials is difficult.³⁸ Currently, it is unclear which specific types of red lakes were used in Van der Weyden’s Lamentation. The upper layers of a cross-section from the orange kirtle (Fig. 6d) appear to contain two types of red lake particles, each with a different fluorescence in UV illumination. The orange-pink fluorescence of some particles suggests madder, but the dyestuff of the red lake(s) has not been confirmed. A combination of MA-XRF scanning of the painting and scanning electron microscopy–electron dispersive X-radiography (SEM-EDX) analysis of cross-sections confirmed that red lakes used in different areas of the Lamentation were precipitated on substrates containing calcium (Ca), aluminium (Al), and/or potassium (K).

During the reconstruction exercise, the students had access to several madder lakes.³⁹ Unfortunately, kermes was not available, so a different insect-based dyestuff (lac dye made from the secretions of Coccus Lacta) was used. The students chose the lake that seemed to “work best” for them, meaning that it had the desired working or colour properties. For this reason, it is difficult to draw firm conclusions about the lakes that Van der Weyden might have used. The exercise, however, demonstrated that red lakes made from different raw materials or recipes each have a distinct colour, and that even a very small admixture of red lake can have quite a dramatic effect on the colour of a paint. For Van der Weyden, it would have given a “blue” drapery a lilac or purple colour (see Question 3a), and provided modelling in a sleeve (Question 3b). Red lake applied as a thin glaze would have intensified and deepened colours, including the brown dress (Question 3b). We also observed that such colour effects are subject to change in both the short and longer term, and that changes can deeply affect the colour balance in a painting, eventually leading to seemingly unusual shades or combinations (Questions 3a and 3b).

4. How might the artist have achieved small reflective details, like gems and drops of blood?

Once the landscape, figures, and clothing had been laid in, Van der Weyden applied small details to enliven the painted surface: gems, tears, blood, and reflections on metal. By reconstructing these details, the students came to understand how he was able to convincingly depict small objects that are meant to appear reflective, translucent, or shiny.⁴⁰

Mary Magdalene’s clothing is lavishly decorated with pearls, gems, and gold threads (Figs. 2a, 8a). Although he used real gold to embellish the edges of the garments, Van der Weyden created the other details with paint only. The student who reconstructed this detail tried to follow the same steps (Fig. 8b). He presumed that painting the gems would be complicated, but when he examined microphotographs, he noticed that they are similar to each other and rather schematic. The challenge lay in the timing; he had only a few days to complete them. Mary Magdalene’s neckline is embellished with pearls and red and blue gems, painted on top of a brown paint layer (Fig. 8a). This brown colour established the base tone for the metal setting around each gem; on top, he applied a darker brown shadow as a half-circle underneath and a bright reflection in the upper left. To reconstruct each gem, the student applied either ultramarine or red lake on top of a brown paint layer. The next day, when he attempted to apply the highlights, the glazes were still wet; the result was less successful because the roundness and reflectivity of the gems relied on crisp highlights in specific places. After waiting for the base tone to dry further, the student proceeded with the application of highlights: first a diffuse reflection on the bottom of each gem, and then a stronger highlight in the upper left.⁴¹

A simpler technique was used to paint the drops of blood dripping from Christ’s wounds (Fig. 8d). The base tone contains vermilion, with small touches of a darker red lake glaze, applied when the vermilion was still wet. The combination of a glossy glaze and tiny dots of lead white created convincing reflections that imitate the viscous liquid.

These reconstructions suggested that the successful imitation of gems and blood droplets depends less on the meticulous rendering of tiny details, and more on adhering to a consistent formula. In his logbook, a student remarked that Van der Weyden would have needed to plan ahead and follow a series of specific steps, with ample time for drying between each.

Conclusion

Reflecting on the experience of reconstructing various sections of Rogier van der Weyden’s Lamentation, all students reported major and minor discoveries that they would never have made if it were not for their physical involvement in every step of the production process. Most of these results have a primarily didactic value. As is often the case in reconstruction-based art-technological research, there is a certain degree of subjectivity that must be taken into account. It is also important to consider that the reported observations are those of novice painters. Nonetheless, the exercise provided some insights into the use of certain materials and techniques, and its effects on the discolouration of the Lamentation.

Challenges in the painting process were educational when it came to understanding what the process of painting was like in the past, with the materials available at the time. It also illuminated practical aspects of the working process that are rarely described in historical sources, or even in modern literature.⁴² One student realised the importance of working from top to bottom, after repeatedly covering her hands in paint and smearing her work.

Occasionally there were surprising results that even the more experienced participants could not have foreseen, such as the initial darkening of a specific type of red lake, contrary to the fading that is so commonly described. Results like this evoke questions about the relative stability of various types of red lakes and their relation to the appearance of paintings over the course of time. Other questions were less easy to answer, like determining precisely which underdrawing tools were used in the original artwork. Even though the images produced by infrared camera suggest that the underdrawing of the reconstructions came quite close to the appearance of the original drawing, it remains a question to what extent fifteenth-century painters adapted the thickness of their lines anticipating the subsequent paint layers. It did, however, become clear that the absence of split ends in the underdrawn lines does not automatically exclude the use of a quill, and that it is possible to apply both broad and fine lines with a quill. Insight was also extended to the role of tinted intermediate layers in the work of Van der Weyden. The experience showed how such a layer would have toned down an underdrawing to a significant extent, and how its colour may have affected the number of layers required to achieve a convincing skin tone. Moreover, it became evident how the choice of a certain processed oil as a binding medium for such a layer may have influenced paint handling in subsequent layers.

A crucial element of this study was examining the reconstructions with some of the same scientific methods that were also applied to the real painting. Comparing the results from infrared examination and/or analysis of samples showed the ways in which the reconstructions are similar to – or different from – the original. Although it is impossible to say anything conclusive about the original appearance of the draperies in the Lamentation based on reconstructions alone, comparing the reconstructions and original artwork has yielded valuable insights about the visual impact of change, and the effects of specific materials and application techniques on their ageing processes. In other words, we do not necessarily know exactly how the colours originally looked, but we have increased our understanding of the factors that were of influence. We witnessed the dramatic effect of fading red lakes, both on the colour of individual areas and the balance between them. Although the fading of lakes is nothing new, and the exact amount of fading is impossible to assess, the fresh colours of the reconstructions do provide a reference that helps us imagine the original splendour of the artwork. We also saw how different approaches to the modelling of blue draperies may well explain why in some places all three-dimensionality has been lost, while in others it is comparably well preserved. Some students were surprised by the tinting effect of even the smallest addition of red lake, as well as its particular colour. Two different lakes based on the same raw material could make the difference between a warm orange-red and a cool one tending towards purple. This underpins the need for more thorough analysis of remnants of various lakes on early Netherlandish paintings.

Making these historically informed reconstructions was a humbling experience. Regardless of the body of data we now have on the Lamentation, there was always some crucial information missing. Although some of the reconstructions came close to mimicking Van der Weyden’s finest details, all the students were happy to acknowledge that they would need more practice to become a master.

Acknowledgments

Edwin Buijsen (Mauritshuis), Kirsten Derks (University of Antwerp), Harlie Des Roches, Lieve d’Hont (University of Amsterdam), Anne-Sofie Hamers (Technical Art History student), Ralph Haswell (Shell Technology Centre Amsterdam), Erma Hermens (University of Amsterdam/Rijksmuseum), Arjan de Koomen (University of Amsterdam), Ingrid Kramer (Technical Art History student), Paul van Laar (Technical Art History student), Annelies van Loon (Mauritshuis/Rijksmuseum), Herman den Otter (University of Amsterdam), Sabrina Meloni (Mauritshuis), Ariane van Suchtelen (Mauritshuis), Margareta Svensson, Mané van Veldhuizen (Technical Art History student).

Table 1. Materials Used in Reconstructions

^a Indra Kneepkens, “Masterful Mixtures: Practical Aspects of Fifteenth- and Early Sixteenth-Century Oil Paint Formulation” (PhD diss., University of Amsterdam, 2021).

^b Made according to “ML-Std” and “ML-pot-Al” recipes in Kirby, van Bommel, and Verheken, Natural Colorants for Dyeing and Lake Pigments, 91–92.

Notes