This paper is published in the book ‘Subliming Surfaces: Volatile Binding Media in Heritage Conservation’, ed. Christina Rozeik (University of Cambridge Museums, 2018), pp. 67-78.The objective of this project is to observe the formation and changing structure of CDD crystals and their effect on painted porous surfaces. To investigate the interaction of CDD with absorbent and weak substrates, mock-ups of fragile painted plaster were prepared and CDD was applied to each of the mock-ups as either a hot melt or dissolved in Stoddard solvent. Time-lapse microphotography recorded the behaviour of the CDD crystals regularly over a span of six weeks. Scanning electron microscopy and confocal microscopy were utilised before application and after sublimation of CDD to characterise the surface morphology and porosity of the substrate, and to observe any damage that the CDD crystals may have caused to the surface of the artefact. Three computations were used in conjuction with confocal microscopy in order to analyse the topographic deviations caused by CDD interaction: surface subtraction, profile extraction, and horizontal contour extraction. It was concluded that CDD may be altering the original surface of the samples by widening pre-existing cracks, altering particle morphology, and inducing minor elevation changes in the overall topography. However, it does not impart a new texture to the plaster nor does it appear to cause new or original cracks in the substrate
