It is quite often that the works we examine in the Paintings Studio at the Williamstown Art Conservation Center have been previously repaired, restored, and conserved– the terms are varied– and we are tasked with assessing not only the artwork itself, but the work done to it.

Case in point: a privately owned 16th-century Netherlandish triptych, having been on long-term loan to the Hood Museum at Dartmouth College since the 1960s, was being considered by a graduate student for an exhibition a few years ago. The condition of the altarpiece was in an unexhibitable state; therefore, a full examination, proposal, and treatment was requested.

Before Treatment: Studio of Pieter Coecke van Aelst (attr.), Netherlandish Triptych , c. 16th century, Oil on panel, Open: 33” x 47 ½” Closed: 33” x 23 ½”, Private Owner
This 16th-century Netherlandish triptych, a “painting with doors” [1], is intended as a devotional altarpiece; the three panel paintings are adorned with a religious narrative to inspire those who consumed it. This specific altarpiece depicts three common scenes in Christian art (Fig. 1): The Adoration of the Magi, showing The Three Kings bestow gifts following the birth of Christ (Fig. 2); The Rest on the Flight into Egypt, illustrating the Holy Family in a brief moment of respite on their journey while escaping the Massacre of the Innocents (Fig.3); and The Annunciation, where we see the Angel Gabriel revealing Christ’s conception to the Virgin Mary (Fig.4). Traditionally, the doors are interpreted as a boundary between the sacred realm and the viewer. The doors would typically be opened or closed depending on both the time of worship and liturgical time of year; thus, the reverse of doors were often painted with an alternate scene to accompany the central narratives inside. The outer doors may reference the patron saints after which a Church was named, including landscape or sculptural elements. The shape of the triptych’s framework– the engaged frame– presents the triptych as an architectural structure, mimicking grand cathedrals as a place of worship. The triptych’s overall ease of portability suggests that this particular altarpiece was likely commissioned for private devotion, suiting a small chapel in a wealthy household or modest Church.
FIGURE 2 . Detail, Central Panel: The Adoration of the Magi
Detail, Right Panel: Rest on the Flight into Egypt
Detail, Left Panel: The Annunciation
In distinct contrast and arguably more mesmerizing, the palette of colors and decoration of imagery throughout these paintings inspire tactile daydreams about the luxurious fabrics, precious jewels and gleaming metals that grace the surfaces of these panels. This triptych is currently attributed to the artist Pieter Coecke van Aelst (and Studio), based in Antwerp, and proficient in a wide range of arts such as painting, tapestry, prints, stained glass and goldsmithing. The artist and his studio produced objects that travelled the world during his lifetime. These objects were coveted by their patrons and continue to marvel viewers centuries later [2]. The epitome of a “Renaissance Man”, Pieter Coecke van Aelst produced a diverse legacy of artworks, and it seems comfortably fitting that this triptych is attributed to his name. The altarpiece wholly encompasses the trademark style of the “Antwerp Mannerists” [3], solidly rooting it in the cosmopolitan and booming culture of 16th century Antwerp.   The condition of this triptych gives suggestive glimpses into the potential handling of this object by previous owners, giving function to form. The heavily worn hinges that attach the doors to the central panel have most likely been damaged from countless openings and closings (Fig. 5). The disrupted and buckled paint layer in the space between the bodies of Joseph, Mary, and Jesus in The Adoration of the Magi could have resulted from a candle flame hovering too close to the surface upon inspection in dim light (Fig. 6). A collection of deep holes on the reverse of the upper frame curve for the central panel is assumed to be the trace of an old hanging mechanism (Fig. 7). These prosaic sentiments are fitting to the spiritual aspirations this altarpiece provided as a religious tool forged in 16th century Netherlands, a society in the grips of Protestant Reformation.
FIGURE 5. Detail of the worn hinges
FIGURE 6. Detail of disrupted paint between the bodies of Mary and Joseph
Unfortunately, due to a possible change in aesthetic preference or damage, part of the delicate and mesmerizing handling of Aelst studio’s work was obscured by previous treatments. The most obvious of aesthetic interventions on the 16th-century triptych in our studio was the black overpaint covering the composition of the outer doors and majority of the engaged frame. It was clear that it was overpaint at first glance, because flake loss revealed painted parts of a different passage. There is an undeniable historical precedent of artworks being modified in the interests of censorship, changing religious beliefs, fading fashions, or uncontrolled hubris– to name a few catalysts. This triptych was likely a victim of the Reformation, a moment of religious upheaval between the Protestants and Catholics in 16th-century Europe. The black overpaint could very well have been a consequence of Catholicism losing favor; covering any overtly Catholic imagery protected not only the triptych itself from destruction, but censoring the artwork also protected the patron from persecution. For a more globally-famous point of comparison to the triptych in our studio,
a recent conservation campaign discovered that the Ghent Altarpiece
[4] had endured significant alterations to the original imagery, uncovered during the cleaning of the recognizable 15th-century polyptych [5]. Post treatment, the anthropomorphized face of The Lamb of God has returned to its original state in the Adoration of the Mystic Lamb since an unwarranted 16th-century alteration was removed. This case did not specifically occur due to the Reformation; however, it is an exemplary case of change in stylistic preferences carried out by a historic restoration. While the true motivations behind the application of overpaint were elusive at initial examination, understanding and unpacking all the layers of modification became a key goal through the first phase of treatment: surface cleaning the triptych. This article is part I of II in a series that will discuss the extensive treatment and understanding of this object. Treatment is currently ongoing in the studio and analysis is being carried out on paint samples to contextualize and appreciate the materials and techniques used to create this beautiful triptych. This part will discuss at length the condition of the triptych as it arrived in the studio, and focus on the cleaning and structural phase of the treatment; part II will discuss the rest of the treatment and present findings related to its construction and original appearance.
FIGURE 7. Reverse of the tryptich: note the holes on the reverse of the upper frame
FIGURE 8. Doors closed, front of the triptych
The initial condition assessment began by looking at the triptych in a closed position (Fig. 8). A thick, black coating covered the majority of the outer doors and frame, apart from areas of damage and a cleaning test window on the proper left panel. An oxidized label was glued to the proper right panel over the black paint: a paper clipping from what reads to be an auction catalogue, written in French, and describing the scenes depicted on the inner panel paintings (Fig. 9). Wax (estimated beeswax mixture) had been unevenly spread across most surfaces. It appears that this wax was intentionally applied as a consolidation adhesive, meant to address detachment issues between the paint layers of the triptych. While rarely used in current practice, the role of wax in paintings conservation can be traced back hundreds of years, typically favored in locales where combatting a humid climate is a constant battle. In comparison to the outer panels, the reverse of the central panel and frame (Fig. 7) exhibit a semi-gloss sheen, appearing to have a thin wax surface coating penetrating the wood and softly buffed through handling over time. This application of wax could very well point to a treatment specifically meant to mitigate naturally humid climates – even a humid microclimate such as a hanging position on a poorly-insulated exterior wall. Unfortunately, in contrast to the wax barrier, the wax consolidation effort on the triptych had begun to fail in recent years, evidenced by fresh paint losses. These paint losses exposed remnants of a white ground layer and the barely-oxidized wood of the frame and panels, standing out against the stark black overpaint ( Fig. 8).
FIGURE 9. Detail of label adhered to the proper right panel
Heavily-cupped paint– therefore, very vulnerable paint– was visible throughout an evenly dispersed craquelure pattern. This fine, geometric pattern of cracks is indicative of the wood panel support and incredibly common in aged oil paintings on wood panels. As a hygroscopic material, wood is prone to expanding and contracting when responding to changes in relative humidity (RH). The severity of hygroscopic movement is dictated by factors such as cut and species of wood, causing a typically uniform crack pattern to develop throughout the paint as the oil film dries and ages. While craquelure is not outright concerning, the sharp edges of cupped paint are susceptible to snapping off and the disrupted adhesion to the panel support could mean full flake loss. This was a large concern for handling or moving the triptych, as any snags from contact or strong vibration from movement could result in new damage or further loss of original media. Carefully opening the doors of the triptych, the consolidation effort was clearly applied to the inside of the altarpiece as well. It appeared that there were more localized applications of wax along each split in the wood panels, with five significant vertical splits counted (three on the proper left panel, two in the central panel). Wax was also liberally injected into the gaps where the individual panels meet the engaged frame (Fig.10). This method of treatment was estimated to be an attempt to stabilize the splits and secure the panels in place; however, targeting the space between the panels and engaged frame could have unintentionally caused more damage to the structure. The inherent expansion and contraction of wood is oftentimes referred to as “play”, and significant restrictions to this movement can result in detrimental forces upsetting the overall structure of a panel painting. This is the reasoning behind why panel paintings paired with more typical frames are recommended to be secured into a padded rebate using clips (ideally flexible spring clips) solely oriented in the direction of the panel’s wood grain.
FIGURE 10. Detail of wax residues between the edge of the frame and panel
The more bespoke pairing of panel paintings and engaged frames has a long and purposeful history. Hewn and assembled by expert cabinet makers and wood workers, engaged frames were designed to allow for freedom of play and intentional preservation of panel paintings. A missing piece of the triptych frame on the reverse of the central panel, upper proper right corner (Fig. 11), reveals the structural relationship between the paintings and engaged frame. The elongated, stepped edges of the quartered oak panels were carefully trimmed to freely fit into the carved channels of the frame members. The space provided for the panel edges in the grooved channels leave just enough room for play, while the overall structural function of the frame safely contains and displays the paintings. Similarly, the structure of the mortise and tenon joints of the frame members, using opposite-grain wooden fastening pegs (Fig. 12), responds accordingly to its own experiences of movement.
FIGURE 11. Detail of missing piece of the frame
FIGURE 12. Detail of pegs
In the case of the triptych, immobilizing the panels with wax consolidant may have contributed to worsening of splits. The triptych disclosed additional signs of age (it is likely nearly 500 years old) [6] with evidence of shrinkage, loose joints, gouges and missing pieces in the frame, and cracks in the frame members. Overall, the four historic (if not original) metal hinges were very compromised and unstable. Many of the hand-wrought nails were damaged or missing, and a couple of the lost nails were replaced with modern screws. Another historic structural treatment was noted on the reverse of the central panel; two canvas “band-aids” were applied on the left (proper right) side using what appeared to be animal glue to cover splits in the wood (Fig. 7). This treatment is estimated to have been done prior to the 19th century, and the two patches appear to have been applied before the reverse of the center was coated in its uppermost layer of wax. These patches are difficult to accurately pinpoint on a timeline, as the localized reinforcement of wood splits with fabric patches is commonly seen on panel paintings, frequently chosen for hundreds of years as an unobtrusive solution to an unpredictable worsening of splits. The patches on this triptych were not embrittled nor detaching from the reverse, and did not appear to be exerting adverse pressures onto the panel.
There remained the active and broader issue of flaking overpaint (with suspected original paint attached), and additional instances (to a lesser degree) of tenting and loss visible on the paintings inside the triptych. It was clear that the new treatment campaign would have to prioritize removal of the wax consolidant and replacement with a more stable adhesive of greater bond strength to successfully safeguard the triptych. In the instances of wax immobilizing the paintings within the engaged frame, this wax would simply be removed to free up the oak panels again. But, just as there is structural risk of splits appearing in immobilized wood panels, there is also risk involved when releasing stuck panels. Luckily, most of the existing splits did not completely bisect the panels of the triptych, and the cracks did not appear to shift at all when the object was handled. The single complete split is located in the central panel, yet this is sufficiently reinforced on the reverse to bridge the gap and absorb any potential play in the panel while the wax is removed. Proper handling, studio set-up, and mindfulness of all the various physical pressures exerted onto the panels during wax removal would be crucial in the stabilization steps of treating the altarpiece. Even post-wax removal, the canvas patches on the reverse of the central panel were determined to be benign enough materially and historically significant enough that the reversal of this old treatment was not recommended. The precarious attachment of the four door hinges was another important consideration in the structural treatment of the triptych; rather than any drastic alteration of the hinges themselves, the instability of the door attachments would most likely be addressed with a separate mounting system for safe display.
After assessing the structural condition of the triptych and developing a plan for stabilization, I began to consider the cosmetic issues at hand. The black overpaint overshadowed the triptych, giving it a grave visual weight. It also appeared that the gilding inside the frame was overpainted with gold leaf and bronze paints. The heavily discolored natural resin varnish coating the inner paintings drastically dulled and leant a yellowed appearance to the vibrant scenes (Fig. 13), as well as obscuring fine details in the landscaped  background. There were unfilled and minimally retouched losses in these scenes, causing a disruption to the smooth and lauded surface quality unique to panel paintings (Fig. 14). The extant cleaning window of removed overpaint on the outer door gave an exciting glimpse of blue shades, a probable rendering of sky. This window was expanded during the exam to determine ease of overpaint removal. Noticeably, the black coating was thickly applied and stubbornly holding onto the surface, yet patient tests with solvent gels expanded the small scene by revealing the tops of trees and other leafy greenery, undeniably a landscape (Fig. 15). Other scattered losses of overpaint on both the outer panels and inner frame rails revealed small instances of original paint in shades of red, orange, green and brown. These colorful clues, combined with extensive occurrences of the distinct craquelure pattern found on aged panel paintings, indicated that original oil paint layers would be found beneath the overpainted surfaces. More specifically, a glimpse of landscape peeking through the cleaning window on the outer panel suggested that there very well could be full representational paintings hidden beneath the black.
FIGURE 13. Detail of streaky and discolored varnish on The Rest on the Flight into Egypt panel (note cleaning window in upper right of this image)
FIGURE 14. Detail of losses in area of flower vase on The Annunciation panel
FIGURE 15. Detail of cleaning window on outer proper-left panel
After the first layer of overpaint was unpacked, remaining layers of overpaint material proved tenacious and removal became even more tedious. The immediately subsequent layer had the appearance and texture of a thick and porous, calcium-rich ground layer, toned varying shades of black depending on how much solubilized paint had penetrated into it during removal of the first layer. Beneath this “ground”, there appeared yet another layer of black paint, similar to the first layer (Fig. 16). Different solvent mixtures in gelled solutions were used as cleaning progressed to better target the layers situated closer to the original paint layers. Greater caution was necessary as removal of the overpaint exposed more original paint. . The focus remained on revealing the original composition on the outer panel paintings, thus techniques to provide a protective barrier to the original paint layer were employed. The first isolating material chosen was a natural resin varnish mixture containing mastic (resin from the Pistacia lentiscus) and dammar (umbrella term for various resins derived from trees in the family Dipterocarpaceae). This application of working varnish isolated the fully-cleaned surfaces, lending some protection against the solvents and mechanical action used on the remaining islands of overpaint ( Fig. 17). Two-fold in function, the working varnish saturated the original paint layers for better working visibility and also increased the ease of overpaint removal. The miniscule molecule size of the natural resins, particularly mastic, allowed the working varnish to penetrate into the porous structure, “bonding” to the overpaint during the drying process ( Fig. 18). The known reversibility of the natural resins facilitated an easier removal of the black paint after the working varnish was allowed to sit on the altarpiece for at least a few days before resuming the cleaning process.
FIGURE 16. Detail of overpaint materials during cleaning on outer panels
FIGURE 17 . During treatment overall of closed triptych with working varnish overtop
In addition to visual cues, an important source of information for this triptych throughout developing a treatment proposal has been the historical context of the work. At this point, samples were taken from the inner frame members for cross-section microscopy to visualize the stratigraphy or original layer structure of the paint on the frame. These findings will be used to inform the retouching used to integrate remaining damage after the painting is consolidated and cleaned; this valuable information will be presented in the next article and phase of this project. The structural instability of the triptych would need to be addressed, and the heavy application of overpaint appeared far too dour and boldly overstepped the intentions of a workshop known for vibrancy and treasure-like artworks. A treatment proposal covering a range of treatment options for the family-owned triptych was presented. The stakeholders– The Hood and private owners– visited the WACC to discuss treatment options for direct reference. Discussions centered around the overpaint and approaches to address it and ultimately, approval was given for an all-encompassing treatment; it was time to see what was hiding beneath.
Vulnerable paint had to be stabilized before the unpacking of overpaint layers could occur. Though it may seem counterproductive to re-consolidate the overpainted surfaces, there would be no safe way to remove the black paint and imitation gilding without loss to the original paint film; otherwise a potential forfeiture of both original media and unwanted overpaint would incur unless the black paint was stabilized prior to removal. To prevent further absorption of wax into the triptych’s support, the wax layers were safely reduced on the surface by applying xylenes with cotton swabs or delicately minimizing it with a scalpel. Once the wax was sufficiently reduced, new consolidation was carried out with diluted BEVA® 371 solution on both the outer doors and inside panels. This adhesive, a thermoplastic ethylene-vinyl acetate (EVA) formulated for art conservation, was chosen due to its success in applications where wax has previously been impregnated into the structure of a painting. To prepare the proprietary adhesive, the BEVA® was diluted with xylenes and heated to flow temperature (around 155 ᐤF). It was then gently wicked into unstable craquelure and paint losses using a fine-tipped brush. The adhesive was kept liquified by continuously heating small amounts on an electric mug warmer, facilitating ease of work flow during the extensive consolidation effort. Pipettes of the diluting solvent (xylenes) were kept close during the process to address instances where the adhesive needed further thinning, or the wicking action was inhibited by wax and flooding the zone with solvent was needed. After the solvents had evaporated out of the BEVA®, any cupped or lifting paint was set down and reattached to the wood substrate with a small heat tool, a WillardⓇ Heated Spatula, utilizing the thermoplastic quality of the adhesive. Stabilized, the triptych was ready to be safely cleaned. The cleaning was approached layer by layer, beginning with removal of surface wax and remaining adhesive residues. As previously done, these were removed using cotton swabs and xylenes; heavy wax deposits were mechanically reduced with a scalpel prior to being wiped away with a solvent swab. The overpainted surfaces were slowly removed on the triptych through various solvent gel actions depending on the layer, targeting the unwanted materials in a controlled manner. Solvent gels are helpful at reducing risk for the conservator and artwork, as far less toxic organic solvent exposure occurs with the relatively small amounts of solvents used in a gel system rather than the heavy amounts of free solvents used with only rolling swabs. Additionally, gels are hygroscopic and facilitate a targeted interaction between the unwanted overpaint, without affecting or minimizing reactions between the chosen solvent and the original paint below. Overall, the solvent gels were also more successful than free solvents at removing the overpaint because of the extended period the gelled solvents spent in contact– therefore solubilizing– unwanted materials on the surface of the triptych. Black overpaint on the outer panels was pursued first. The uppermost layer of black paint was picked up using a solution composed of a polymeric gel (Carbopol® 934), emulsifying agent (Ethomeen® C25), and solvent mixture (80:20 ethanol to xylenes and a small component of water). It was discovered that by applying the gel over a square of thin Japanese tissue and placing a slightly larger square of polyester film (Mylar®) overtop, the uppermost layer of black paint bonded with the entire package after several minutes and could be “peeled” off the surface for disposal. A small amount of free solvents was then used in the appropriate clearance solution to remove any residues of the gel and solubilized overpaint on the surface. The spent gel and tissue glob could then be cleaned off and the Mylar® re-used for future sections. Small windows revealing more original paint began to open up, teasingly confirming the presence of fully representational compositions of two saintly figures: one on each panel set against a detailed landscape. After such success on the outer panels, this initial cleaning technique was applied to the black overpaint on areas inside the triptych.

This video demonstrates the process of cleaning the overpaint from the outerdoors.
As islands of the black overpaint became smaller and smaller, revealing more and more of the original paintings, a mixture of silicone solvents (Phenyl Trimethicone and D5) were applied to the paintings as a protective barrier against the final steps of cleaning; like the natural resin varnish, this mixture saturated the original paint film to provide increased visibility for the delicate removal of remaining overpaint; however, the solvent evaporated after removal and did not require a separate step of removal by solvents that may have affected original paint. A new Carbopal® gel was mixed with a solvent ratio of 80:20 ethanol to ShellSol 15 (≈15% aromatic mineral spirits). This change in solvents allowed for more meticulous cleaning, expanding the working time by replacing xylenes with the slower evaporating and less aromatic mineral spirit.The method of cleaning the outer frame members differed slightly to that used on the outer panels. There was extensive overpaint along the outer frame, however, its primary function was to cover large areas of lost original paint or ground; there were only minor instances of original material hidden underneath the overpaint, much of which appeared to be scattered remnants of a ground layer. The incredibly fragmented state of the outer frame paint layer meant that a large portion of the oak framing was exposed during cleaning. The solvent gel used on the outer frame consisted of a polymeric emulsifier, Pemulen™ TR-2, and benzyl alcohol (<20% w/v) as the organic solvent component. As an emulsion, the Pemulen™ TR-2 gel contains far more water in comparison to the Carbopal® mixture. While exposing raw wood to water can cause irreversible damage, the controlled manner in which this gel was used prevented any unwanted effects. This gel was particularly successful at removing overpaint on the areas of exposed wood because Pemulen™ TR-2 has effective “anti-redeposition” qualities, meaning the black paint would not be unintentionally deposited back onto the surface of the wood when clearing the gel off the surface.
Cleaning began on the inside of the triptych after the composition on the outer doors had been revealed. The discolored varnish coating on the inner panels was kept intact until overpaint removal had been mostly completed on the inner rails, utilizing the protective qualities of a varnish layer by keeping the paintings isolated while cleaning the sight-edge of the frame. The Carbopol®/Ethomeen® gel containing the 80:20 ethanol to ShellSol™ 15 mixture was the most successful at removing the gold and bronze overpaint. Unfortunately, only scattered specks of the original gilding remained intact. However, the bright orange bole, a preparation layer typically unseen and hidden beneath gilding, was nonetheless an exciting reveal. The bole is dotted with various residues of oil paint from when the panel paintings were executed in-frame ( Fig. 19). It was also confirmed that the upper proper left frame member was a replacement piece, as removal of overpaint on this section revealed a different wood grain and did not uncover any original media that was found on all other members (Fig. 20). The deviated orientation of wooden pegs near the frame joints and wonky finishing of the curvature on this member were the first indicators that this was a replaced section, but it certainly appeared to be a very historic repair.
The most surprising of reveals was found after cleaning overpaint off the majority of the inner frame surfaces. Despite being fragmented, it was clear that this frame was still decorated with some of its original polychromy; a brightly colored, faux-stone marbling (Fig. 21a-b). While most altarpiece polychromy is often associated with brightly painted wooden sculptures, polychromatic decoration of engaged frames was widely practiced on triptychs and polyptychs throughout Renaissance Europe. Rare to find an intact and unaltered example nowadays, the engaged frames on most Northern European 16th century altarpieces have been damaged, altered, or replaced entirely. Initial research into Pieter Coecke van Aelst and his contemporaries did not yield any similar examples to the original polychromy found on this altarpiece; however, there are many examples of similarly-altered engaged frames overpainted in stark black [7].
FIGURE 19. Detail of overpainted bole from when paintings were executed in frame
FIGURE 20. Detail of replaced frame member
FIGURE 21a. Details of fragmented original polychromy on frame during cleaning
FIGURE 21b.Details of fragmented original polychromy on frame during cleaning
The discolored varnish and retouch on the inner panels was finally removed with ease, especially when compared to the endeavor of removing the black overpaint. A 4:1 ratio of ethanol to ShellSol™ 15 was used on cotton swabs to roll over and pick up the thick and grimy surface coating, safely cleaning the paintings and uncovering their jewel-toned embellishment ( Fig. 22).
The first phase of treatment was dominated with pails of blackened cleaning swabs and bated breath of unveilings. While the conservation work on the triptych is far from finished, this altarpiece has undergone a dramatic transformation (Fig. 23a-b). The entire process of conservation stewardship for this triptych has been a challenge: to create a set of treatment proposals for the triptych required elaborate consideration due to the faceted nature and uncertainties of the artwork; choosing a treatment plan was an inherently painstaking responsibility; and responding to discoveries throughout the treatment process has become a true test of patience and wonder.

FIGURE 23a . During treatment overall of closed triptych
The transformation is not yet complete, but the trial of cleaning the triptych has no doubt been an enlightening process. The discoveries made during this phase of treatment resulted in numerous questions about the materials and techniques used to make this unique triptych. I look forward to ascertaining more about its construction from the technical analysis being carried out on samples in the WACC analytical lab. This analysis will help inform the retouching in phase II of treatment and provide more clues to how this triptych once looked in 16th century Netherlands. The completed treatment will be revealed in the next Art Conservator.
FIGURE 23b .
During Treatment: Studio of Pieter Coecke van Aelst (attr.), Netherlandish Triptych , c. 16th century, Oil on panel, Open: 33” x 47 ½” Closed: 33” x 23 ½”, Private Owner
[1] For a contemporary art historical take on understanding triptychs, see Opening Doors : The Early Netherlandish Triptych Reinterpreted by Lynn F Jacobs, Pennsylvania State University Press, 2012.
[2] A recent exhibition on Pieter Coecke van Aelst, “Grand Design: Pieter Coecke van Aelst and Renaissance Tapestry”, was organized by the Metropolitan Museum of art in 2014. For more information visit
[3] For a broader understanding of “Antwerp Mannerism”, visit
[4] Hubert and Jan van Eyck, Adoration of the Mystic Lamb, 1432, Polyptych altarpiece, St Bavo's Cathedral, Ghent, Belgium
[5] For an interactive website with high resolution images of the Ghent Altarpiece conservation process, visit
[6] Part II of this article will focus on the art historical context of the composition and structure in order to discern more about its potential age and similarities between this unknown studio production and the materials and techniques of known Netherlandish studios.
[7] For an example of another Northern Renaissance overpainted frame that has only been test-cleaned, see Molly Faries, Henri Defoer, "Jan van Scorel’s Crucifixion for the Oude Kerk, Amsterdam: The “finest painting in all of the regions of Flanders”," Journal of Historians of Netherlandish Art 12:2 (Summer 2020) DOI: 10.5092/jhna.12.2.1