Page - 185 - 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 185 show dark halos around the silver ink lines as well as dark migration on at least one sample. Among these the reference inks ST3 and ST4 show the most pronounced phenomena of ink corrosion, particularly ST4. The ink corrosion and degradation phenomena of dark halos and migration appeared always more pronounced on the thinner Late Antique style parchment (LP). In sub study 2 the reference samples of the reference ink ST14 showed the most serious signs of damage (Fig. 33). ST14 as well as ST13 were prepared for further investigation of the damage developed by ST3 and ST4. ST3 and ST4 were both prepared with wine vinegar and contain either sodium hydrogen carbonate or potassium nitrate. ST13 was produced solely using wine vinegar as a lubricant for the grinding process and contains no further component. ST14 was not prepared using wine vinegar, but contains potassium Fig. 31: Samples ST13_C from sub study 2 after accelerated ageing: a) untreated sam- ple, ST13_B; b) sample treated with salt water. Fig. 32: Macroscopic images (scale bar 1 mm) of samples after accelerated ageing showing the degradation of the inks: a) ST1_B, b) ST4_B, c) ST5_C. Open-Access-Publikation im Sinne der CC-Lizenz BY 4.0