Replicating surface texture: Preliminary testing of molding compound accuracy for surface measurements

The use of surface metrology microscopes to quantify surface texture is a powerful tool for the analysis of archaeological materials. Data collected from these microscopes allows for reliable and reproducible measurements of surface characteristics. However, archaeological materials provide some unique challenges for microscopic analysis, including archaeological objects that cannot leave museums or are too large to observe under a microscope. Because of these challenges, many researchers create molds and casts of an artifact's surface prior to measuring surface texture. The replicate surface is assumed to be an accurate representation of the original surface texture; however, limited testing has been done on the reliability of different molding compounds. This paper uses confocal microscopy to test the fidelity of different molding compounds for surface texture measurements. Results suggest that the objects' original surface texture can pose challenges to the accuracy of molds and the resulting casts, and that the intrinsic texture of the molding material impacts surface measurements of the replicated object.