Paper conservation and restoration - current project

before conservation

removing of the glue from the verso

after conservation

part of the map, during conservation

The conservation of Sancho Gutièrrez's world map

One of the most important objects in the Map Collection of the Austrian National Library is the Sancho Gutièrrez's world map of 1551.

Reasons of conservation greatly limit access to and  usage of this map. As its manner of storage - folded up in a case - presents additional hazards to the map and which by no means conforms to modern archival guidelines, it was decided that a comprehensive conservation and restoration treatment was mandated.

Measuring a total of ca. 1 metre high and 3,3 metres wide, the world map is made of parchment skins joined together. At some point it was cut into 16 segments which were adhered to linen. The recto is severely disfigured by extensive water staining, innumerable worm holes, and tears and lacunae in the margin areas.

Following the development of a treatment plan and thorough documentation, the first step was to protect the sensitive paint layer, for which a 0,5% gelatin/water solution was sprayed on with an ultrasonic nebuliser. Subsequently the dry linen could be removed from the verso. Glue remnants were removed with a methyl-cellulose poultice. Unpainted areas were surface cleaned with cotton swabs.

The next step in the conservation treatment was to close all the wormholes. On the verso the holes were pasted over with a thin Japanese tissue. Then, from the front, as many layers of Japanese tissue as were needed to fill the cavities up to the level of the parchment's surface were glued into each wormhole. Finally, each hole was closed from the top with tiny patches of reconstituted parchment; this material, produced by the Institute for Conservation, combines the elasticity of Japanese tissue with the structure of the parchment and thereby fits itself into the holes very well. In all, over 1,000 holes need to be filled; the restoration of this cartographic treasure is expected to take one year.

last update 2/3/2016