Seite - 96 - in The Vienna Genesis - Material analysis and conservation of a Late Antique illuminated manuscript on purple parchment

96 Purple dyeing of parchment Summary and conclusion The technology of dyeing parchment purple was investigated via practical experiments. Preparation and application methods were tested for orchil, folium and shellfish purple. Parchment can be dyed with all of the three dyes (Fig. 24). A range of vivid hues was achieved with orchil and shellfish purple. The experiments showed that much knowledge and experience are required to correctly process the dyestuffs. The natural products vary and a successful preparation is not guar- anteed, as the orchil batches showed. Furthermore, the results depend on the quality of the parchment. Parchment that seems to be even and perfectly white can turn out blotchy after dyeing (Fig. 25). Different traces of manufacture or individual characteristics of the skin such as scar tissue, spots or patches can be visible and even enhanced on the coloured parchment. The colour varies depending on the species and characteristics of the individ- ual animal. Fig. 23: Comparison of the light aged orchil samples with Vienna Genesis, folio 4, page 7 (left) and folio 7, page 14 (right). Open-Access-Publikation im Sinne der CC-Lizenz BY 4.0