A Comprehensive Review of Recent Glass Condition Surveys for Understanding Glass Collections on a Global Scale

Glass has been used to create objects for function and for beauty for millennia. As a result, glass and glass-containing collection items have made their way into the collections of virtually every cultural heritage institution around the globe. However, despite the ubiquity of glass, only in recent decades has serious attention been paid to the process of glass deterioration, and how deterioration impacts the preservation of items with glass components. Recently, surveys of glass items have been conducted at a number of cultural heritage institutions with large glass holdings. The results of these surveys are typically designed to highlight the trends observed in glass within an individual collection and present the potential applications of these findings to the broader cultural heritage community. The methodologies selected for each of these studies and the types of information reported vary considerably, making direct comparisons between studies complex. In this review, we discuss and compare the methods, results, and conclusions of each of these surveys and make suggestions for best practices for conducting similar studies in the future.