Publication
Title
Darkening of lead white in old master drawings and historic prints : a multi-analytical investigation
Author
Abstract
Old master drawings and historic prints often feature white highlights, which are typically painted using lead white, one of the most widely used historical white pigments. However, it has been observed that many of these highlights discolour over time, becoming dark brown or black due to unclear degradation processes. This phenomenon not only misrepresents the original artefacts, threatening their suitability for public display, but also diminishes their longevity. To ensure their preservation, it is essential to determine why some lead white highlights in these museum objects retain their light tones while others are prone to darkening. The objective of this study was to identify the relationships between the composition, provenance, and production methods of lead white pigments, and their role in the discolouration observed on drawings, lithographs and early photographs. Selected samples and artefacts were examined using a range of analytical techniques, namely X-ray fluorescence spectroscopy (XRF), X-ray powder diffraction (XRPD), and lead isotope analysis. While XRF analyses confirmed the presence of lead as the primary element in the majority of the highlights, XRPD measurements identified a variety of lead compounds such as the carbonates cerussite and hydrocerussite alongside galena-a black crystalline sulfide-and lead sulfates. Additionally, isotope analyses classified the lead raw materials into five main groups. Through these measurements, the examined lead white pigments were categorised based on their compositional properties in relation to the raw materials used, as well as their geographical and temporal origin. A significant finding is that lead white pigments from different production periods, spanning from older to more modern, may be characterised by varying proneness to discolouration irrespective of their provenance.
Language
English
Source (journal)
Microchemical journal. - New York
Publication
New York : 2024
ISSN
0026-265X
0026-265X
DOI
10.1016/J.MICROC.2024.109912
Volume/pages
199 (2024) , p. 1-10
Article Reference
109912
ISI
001166502200001
Full text (Publisher's DOI)
Full text (open access)
The author-created version that incorporates referee comments and is the accepted for publication version Available from 16.01.2025
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identifier
Creation 02.05.2024
Last edited 15.05.2024
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