Seite - 248 - in The Vienna Genesis - Material analysis and conservation of a Late Antique illuminated manuscript on purple parchment

248 Conservation of the Vienna Genesis and the new storage system son with the facsimile editions since 1895. The images of all reproductions were edited and possibly retouched, which makes it difficult to judge differences in the size of small losses or tears in the ink. The folios were also compared with scans from colour transparencies (Kodak Ektachrome) from 1975. No visible changes in the condition of the ink and the paint layer could be detected. Every folio was mounted between two sheets of polyacrylate in the course of the last conservation treatment in 19752. One of those two sheets was adapted with a number of small drilled holes in order to allow some air exchange, see figure 8 in the chapter on the history. Two small pieces of whitish transparent pressure sensitive tape were used to mount the folios on their upper corners on one of the sheets (Fig. 1). The edges of the two poly- acrylate sheets are glued together with transparent pressure sensitive tape that has yellowed. First, each folio was examined through the mounting. Visual examination was done under daylight, transmitted light, raking light, UV light and under magnification3. To enable further visual and scientific analyses as well as conservation measures, the sheets had to be opened. The sheets without the drilled holes were placed face up and wiped with an antistatic cleaning agent (Burnus GmbH) to reduce the electrostatic charge. The pressure sensitive tapes were cut at the edges and the two sheets were slowly separated. During the opening process, a sheet of smooth Japanese tissue (Bib Tengujo, 12 g/m2; Japico) was slid between the parchment and the acrylic sheet to prevent the folios from adhering to the polyacrylate. The adhesive tapes on the upper corners of the folios were cut with a scalpel. The folios were carefully transferred into temporary storage between sheets of Japanese tissue (Bib Tengujo) and museum matboard (Canson, 1.8 mm). 2 Mazal, 1980, p. 193. 3 Microscope Wild M 400, 6.3x–32x. Fig. 1: Small piece of whitish transparent pressure sensitive tape on the upper corner of folio 9. Open-Access-Publikation im Sinne der CC-Lizenz BY 4.0