Page - 193 - in The Vienna Genesis - Material analysis and conservation of a Late Antique illuminated manuscript on purple parchment

Sophie Rabitsch, Antonia Malissa, Katharina Uhlir, Martina Griesser, Christa Hofmann 193 arated fibres out of three different areas of the glass slide, respectively, were analysed and documented photographically. An exemplary comparison of the fibre morphologies which could be observed for the reference parchment NP most frequently after 13 days of accelerated ageing is given in figure 37. The majority of fibres which were present in all fibre samples of this type of parchment appeared to be damaged, mostly in form of “flat fibres” (Fig. 37 d), “pearls on a string” and “bundles” (Fig. 37 b and c) as well as in a transition state from “pearls on a string” to “bundles” (Fig. 37 a). Due to the fact that the fibre morphologies observed are the direct initial stages to partly and completely gelatinised fibres, they indicate an ad- vanced degradation of the collagen structure65. In contrary to the samples of the reference parchment NP, much thinner fibres were present in the samples of the reference parchment LP, which was produced according to Late Antique methods. Due to that, the observation of the fibre morphologies was more complicated. Furthermore, the samples of the parchment type LP showed a smaller amount of damaged fibres. The fibre morphology that could be observed most frequently was “pearls on a string” (Fig. 38). 65 Axelsson et al., 2016, pp. 46–57. Fig. 37: HIROX images (taken at 150x magnification, scale bar 500 µm) of the most frequently ob- served fibre morphologies of reference parchment NP after 13 days of artificial ageing. Open-Access-Publikation im Sinne der CC-Lizenz BY 4.0