Stretch for documents with impressed seals
Many archives store a large number of parchment documents with affixed or impressed seals. These documents cause special problems regarding the storage and space requirements. The most common kind of storage is the storage in document bags, seldomly the documents are lying flatly in cabinets. The hanging storage known as “Kölner System” is an exception. Most archives cannot realise the two last-mentioned kinds of storage due to space or financial reasons.
In order to archive the eldest documents (9th to 13th century) with impressed seals more gently, at least, the Staatsarchiv Darmstadt decided in 1997 to store this part of the inventory as well as oversize formats and other precious documents lying flatly in cabinets. In order to store the documents in bags they had been folded up to 6 times, due to their format. The folding of documents had been the usual kind of storage in the time of their origin. It had become a conservatory problem when the archives were entrusted with the constant preservation.
In connection with this procedure two problems had to be solved:
1. How should the documents be stored in the cabinets?
2. How could the tension be eliminated which had been created by folding, especially in case of the documents with impressed seals.
The first problems could be solved by special panels. If you are interested in these panels please contact Mr. Hofferberth (address below).
The second problem required careful consideration which resulted in the idea of the stretch board. The stretch board is a flexible module system that can easily be adapted to the size of the documents and can be dismanteld and easily stored when not in use.
The individual aluminium modules are 25 x 25 cm and 5mm thick. The aluminium plates have threaded holes at regular intervals. The individual modules are attached to each other with connecting pieces to achieve the required size. The document is then mounted on the stretch board by means of clamps, rubber bands and screws and is dampened before being gently stretched.
Necessary additional accessories:
– Book screws made of plastic
– rubber bands
– wooden slats from laboratory shops
– clamps made of makrolan
– hole screws
Afther the necessary preliminary works (cleaning) the document can be stretched. Please cut a blotter cardboard in the size of the document and put the document on it. The cardboard remains under the document also during the stretching and protects the seal. During the application of the clamps one has to look for a very close application. Smaller breaks at the edges ar no risk but have to be covered by the clamps. For better adherence the clamps are fitted with cardboard which can be easily exchanged.
The rubber bands are pulled through the outer free holes of the clamps and need to be interlooped once. Now the document can be aligned to the middle of the plate. then screw on ring screw in front of every rubber band in the plate and pull the rubber band through the opening of the eye screw. The band has to be interlooped once. By turning the screw you can now apply the first tension. You can fix the tension by means of the wooden slats which can be fed into the rings. One slat can fix several screws. An individual screw can be fixed by adding a second screw into the next winding. This means that every rubber band can be strained even when it is fixed to one clamp.
This first tension should not be to firm in order to leave some tolerance to the document. After covering the seal the object can be spraid with a mixture of water and alcohol (50%). Don’t spray directly onto the document but le a fine mist go down. Then wait some minutes until the document has absorbed the humidity. Now you can adapt the tension until the same tension is applied to every rubber band. This can be easily controlled by tapping on the rubber bands. Depending on the climate conditions of the room the document can be removed from the plate after two days. As far as this is applicable to parchment the document is now flat and does not intend to fold up again.
We would like to point out that this method is only destined for elimination of tension which has arisen due to folding of parchments with impressed seals. In case of parchments with annexed seals and a bending this is only possible conditionally as the folded corner is not totally caught by the clamps which means that it can raise after drying.
Set consisting of: 9 plates, 250 x 250 x 5 mm
8 connecting modules, 45 x 45 x 5 mm
4 connecting modules, 45 x 25 x 5 mm
clamps, eye screws, nuts, screws, wood sticks
rubber bands and book screws made of brass
Additional module for stretchboard: enlargement of working surface for 1 segment incl. accessories
Design: Jürgen Hofferbert, conservator, Hessisches Staatsarchiv, Darmstadt