Table 1 Details of parchment specimens investigated including GAB constants and specific surface areas obtained from the regression of the experimental data for water vapour sorption
Code | Parchment material, time of production | Grammage (g/m2) | Thickness (mm) | Adsorption branch | Desorption branch | |||||
|---|---|---|---|---|---|---|---|---|---|---|
Vm | c | k | sGAB (m2/g) | Vm | c | k | ||||
C | Contemporary parchment produced in a manner similar to the historical material | 180 | 0.23 | 14.2 | 7.66 | 0.71 | 542 | 16.0 | 14.1 | 0.63 |
H1 | Specimen OR32, reference collection of UCL Institute for Sustainable Heritage, a UK legal document, 1868 | 126 | 0.18 | 15.9 | 6.31 | 0.66 | 607 | 18.7 | 12.3 | 0.53 |
H2 | Specimen OR37, reference collection of UCL Institute for Sustainable Heritage, a UK legal document, 1868 | 102 | 0.12 | 14.5 | 6.63 | 0.70 | 552 | 17.3 | 12.1 | 0.57 |
H3 | Specimen OR43, reference collection of UCL Institute for Sustainable Heritage, a French document, 1731 | 169 | 0.21 | 14.4 | 8.02 | 0.68 | 550 | 17.1 | 14.4 | 0.56 |
H4 | Specimen OR59, reference collection of UCL Institute for Sustainable Heritage, a UK legal document, 1906 | 140 | 0.15 | 13.1 | 6.80 | 0.73 | 500 | 17.0 | 11.1 | 0.57 |
H5 | Specimen from the National Archive in Krakow, 18th century | 278 | 0.28 | 14.1 | 1.63 | 0.69 | 538 | 19.7 | 3.36 | 0.45 |
H6 | Specimen from a French legal document,1706 | 97 | 0.13 | 13.1 | 8.25 | 0.70 | 504 | 16.3 | 16.5 | 0.60 |
H7 | Specimen from an Abyssinian book, 19th century | 181 | 0.21 | 14.5 | 7.00 | 0.65 | 552 | 17.03 | 14.73 | 0.54 |