Literature review: The use of Paraloid B-72 as a surface consolidant for stained glass

This paper was originally commissioned by English Heritage, the government's statutory adviser on archaeology and the historic environment in England, in the mid-1990s following concerns over the suitability of Paraloid B-72 for consolidation of loose paint in stained glass conservation. Paraloid B-72 has regularly been utilized for the re-adhesion of loose paint. But in spite of its many advantages (ease of use, reversibility; good aging properties, stability, and miscibility with several types of solvent), legitimate questions have been raised over its limitations (poor resistance to humidity, relatively weak bond with vitreous substrates, and solvent hazards). This article begins with a description of the chemistry and characteristics of Paraloid B-72 and its application in the conservation of historic painted glass. There follows a review of the current state of research on and practical experiences in the use of Paraloid B-72 and related systems. The article incorporates a summary of the known and tested properties of Paraloid B-72 in comparison with alternative materials currently under scrutiny for use in stained glass conservation and discusses the longer-term effects of treatment and the need for continued assessment of their efficacy.