Eraser cleaning of gypsum plaster: Evaluating damage potential using reflectance transformation imaging

Kathryn Brugioni

Abstract

Practically all methods for dry-cleaning gypsum plaster involve abrasion on some scale. Previous studies of abrasion-cleaning methods have successfully quantified damage potential by imaging test coupons in a scanning electron microscope; however, this instrumentation is not available to everyone. Furthermore, the photomicrographs used show a level of detail that will never be perceptible to the human eye. In the absence of scanning electron microscope analysis, a more accessible method for measuring surface abrasion should be assayed: reflectance transformation imaging. This study explores the extent to which reflectance transformation imaging can reveal these surface changes to gypsum plaster caused by multiple dry-cleaning materials. Reflectance transformation imaging captures were compared to scanning electron microscope photomicrographs, which allowed for a calibration of the data collected with reflectance transformation imaging.

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2015 | Miami | Volume 22