Seite - 98 - in The Vienna Genesis - Material analysis and conservation of a Late Antique illuminated manuscript on purple parchment

98 Purple dyeing of parchment swab does not necessarily produce visible traces. When using folium, a dye bath seems more practical, because the dye often results in light shades. The method of applying folium via a cloth that is pressed in contact with the parchment was not investigated. If the colorants are freshly processed and used, the addition of a binder is not necessary and the liquid colorant can be directly applied with a suitable tool or in a dye bath. When dyeing with shellfish purple, a bath is necessary to receive even results. If this dyestuff would be applied with a tool, the oxidation process would happen before the contact with the parchment. The parchment of the Vienna Genesis is completely penetrated by the purple dye. No lighter core section of parchment is visible in cross-section. Colour penetration of a thin parchment can be achieved by immersion as well as by multiple applications of dye with a tool (Fig. 26). Fig. 25: White piece of parchment before dyeing (above), blotchy appearance after dyeing (below). Fig. 26: Cross section of micro samples from the Codex Brixianus (top), a parchment dyed with orchil (middle) and a parchment painted with orchil (bottom). Open-Access-Publikation im Sinne der CC-Lizenz BY 4.0