Page - 86 - in The Vienna Genesis - Material analysis and conservation of a Late Antique illuminated manuscript on purple parchment

86 Purple dyeing of parchment the Göttinger & Berliner Musterbuch, the Trierer Malerbuch, Le Begues Tabula and the Illuminierbuch of Boltz von Ruffach90. The shades of folium are often light and delicate. The colorant is also very light sensi- tive. In order to preserve and store the colour, small pieces of linen cloth were soaked in the sap of the plant parts. They were hung to dry above containers with dung or stale urine, in an ammoniac atmosphere to achieve blue hues. This process was repeated until the fabric had the desired intensity91. The dry cloth could be wetted again to extract and use the colorant. Anne-Marie Brunet, Nathalie Poulain Siloe and Patricia Roger Puyo con- ducted experiments with damp sheets coloured with folium that were brought in contact with parchment by pressing92. From the transfer, visible marks remain on the parchment, which could be observed on the pages of St. Riquier’s Gospels93. By the end of the 14th cen- tury, folium seems to disappear from recipes of colour treatises, while madder, kermes and Brazil wood occur more often94. Preparation Prof. Luigi Menghini95 kindly provided dried fruits of Chrozophora tinctoria, collected in Sardinia, Italy. The fruits have to be processed while still fresh or, if this is not possible, have to be dried for later processing. A recipe provided by Maurizio Aceto was used. First, the dried ripe purple fruits, which result in shades of purple, were separated from the unripe blue and green ones, which result in a blue colour. The purple fruits were further processed (Fig. 12). After removing the seeds, 4.5 g of the fruit husks were placed in a glass filled with 60 ml of tap water and stirred for about half an hour on a magnetic stirrer. The water turned deep red immediately. The liquid was poured into a petri dish and left to dry until the following day. As the extract did not evaporate overnight, the petri dish was warmed in order to dry the extract. The result was a dark red deposit (Fig. 13). 90 Roosen-Runge, 1988, p. 81. 91 Cardon, 2007, p. 493. 92 Denoël et al., 2018, p. 9 93 Abbeville, MS004. 94 Denoël et al., 2018, p. 8. 95 Prof. Luigi Menghini, Università G. d’Annunzio, Dipartimento di Farmacia, 66100 Chieti, Italy. Open-Access-Publikation im Sinne der CC-Lizenz BY 4.0