11:40 – 12:05. LECTURE
Black tears on a black and white wooden sculpture by Nicholas Pope: Resin bleed and problem analysis.

Welmoed Kreb*, Tirza Mol, Sanneke Stigter, Marcel van der Sande, Paul van Duin

Abstract
This paper presents the findings of the research project Processes of Physical Emergence of Resin Bleed: Causes, Prevention, Treatment (POPE: Resin Bleed). The project aims to gain a better understanding of the processes leading to resin bleed in wood and how to prevent and treat this in works of art, with reference to the black and white painted wooden sculpture The Church, the Village and Myself (1986) by the British/Australian artist Nicholas Pope (1949) from the Kröller-Müller Museum collection.
Objects made from resinous wood may occasionally suffer from resin bleed, a phenomenon where natural resin from the wooden substrate emerges to the surface of the object forming distinctive brown droplets. This can occur even decades after the wood has been processed, sometimes disrupting finishing layers if present. Various sculptures by Nicholas Pope demonstrate the phenomenon, leading to drippings, stickiness, paint loss and an overall disturbed appearance, very prominently in The Church, the Village and Myself (1986). The sculpture is intended to feature as a key object in the exhibition The love of art comes first. Art & Project at the Kröller-Müller Museum, opening 30 September 2023.
The phenomenon of resin bleed has been studied in the context of agriculture and the coatings industry but has not yet been studied in the field of art conservation. In this interdisciplinary research project, funded by the Netherlands Institute for Conservation+Art+Science (NICAS), experts from the Rijksmuseum Amsterdam, Kröller-Müller Museum, Cultural Heritage Agency of the Netherlands, and the University of Amsterdam join forces to better understand the problem of resin bleed in general and to assess the conservation problem of Pope’s sculpture with resin bleed in particular, addressing questions of appropriate storage, display and treatment of the artwork.
In addition to archival research into the artwork’s exhibition and storage history, an artist interview has been conducted to document Pope’s use of materials and techniques, his ideas on the altered appearance of his work and his opinion on treatment options. Furthermore, technical analysis has been carried out to determine the chemical and structural composition of the materials, the distribution of the resin throughout the object and its thermodynamic behaviour. The wood is possibly not a common timber species and has yet to be identified. Py-GCMS1 and ASAP2 analysis identified a sesquiterpenoid resin with atlantone and acerenol components, which could point to the genus of the cedars. X-ray illumination did not reveal any resin pockets that could account for the amount of resin on the surface. Py-GCMS suggests a paint based on alkyd resin possibly with the addition of oil, whereas Pope mentioned emulsion wall paint. Differential Scanning Calorimetry indicates that samples of cured resin have a high or no Tg, suggesting that they will not run at room temperature, while the uncured resin has a Tg of -12 °C, indicating that it might still run at room temperature.

1 Pyrolysis–gas chromatography–mass spectrometry
2 Atmospheric Solids Analysis Probe Mass Spectrometry
Pope claimed that he does not mind a small black tear on his work as a natural phenomenon of aging and indication of his use of materials, but the drastic nature of the bleeding, partially leading to a smearing of the
paint is not an intended or accepted part of his work. Research is ongoing and the results will be discussed with various conservation experts and museum professionals to inform decision-making on an appropriate treatment or conservation strategy to resolve the aesthetically disturbing physical-chemically induced damage before the exhibition opens, bearing in mind the practical limitations, ethical considerations and the artist’s expectations. The problem analysis and treatment strategy may serve as an example for the conservation of other cultural heritage objects with resin bleed.