Evaluation of the relief line and the contour line on Greek red-figure vases using reflectance transformation imaging and three-dimensional laser scanning confocal microscopy

The relief and contour lines on a group of ancient Greek red-figure vases and vase fragments in the collection of the Harvard Art Museums and the Worcester Art Museum were examined using two surface examination methods - reflectance transformation imaging and three-dimensional laser scanning confocal microscopy. These methods helped characterize the lines and answer questions regarding tools, techniques, and production sequence used by Greek vase painters. This research also incorporated fabricated mock-ups to gain a better understanding of the ancient technology and in so doing confirmed that the relief lines were not produced by an extruded method, but with a brush made with only a few hairs, termed linierhaar as first proposed by Gerard Seiterle in 1976. Furthermore, it was discovered that not one but two distinct types of relief lines exist on these ancient vases: the laid line (proposed by Seiterle) which has a characteristic ridged profile, and the pulled line (proposed in a previous publication by the authors) which has a furrowed profile. It was also determined that the relief line used to outline figures was applied prior to the contour line in Attic vase decoration, although variations in this sequence occur in vases from South Italy. Based on observations made during this research, the authors propose a likely evolution for the techniques used to produce decorative features throughout the period of red-figure vase production.