An Old Wedding Certificate Can Be Very Brittle
To simply force the document open can cause weak folds and creases to break. In order to safely treat the document its a good idea to rehydrate and raise the moisture content of the paper. How do you do this?
The dry embrittled fibers of old paper documents can be relaxed by slowly raising the amount of moisture in the paper. The size of the document will dictate how large a container is needed. A plastic ice chest will serve for most purposes. The basic idea is to place the paper into a moist environment without it actually getting it wet. In a plastic ice chest fill with about 2 inches of distilled water. Find something that will serve as a rack on which to place the rolled document. You want to place the paper on the rack and close the ice chest. Don’t choose a rack that might rust and stain the paper. Use great caution in not allowing the paper to get wet. Use great caution in not allowing the paper to get wet.
Once enclosed the moisture of the paper will raise its water content over a few hours to a few days. Check the paper for a feel as to its flexibility and how relaxed it has become. Remove from the chest and with care start to unroll the certificate, place some non-abrasive weights on the ends where you start to unroll. Stop this process if the paper has not yet become hydrated enough and return to the ice chest for more time. If it is responding without damage continue until it is flat and place weighted objects on the four corners. Blotting paper is an excellent material to sandwich the document. With adequate sized boards you can then sandwich the document and blotting paper. With this laying nice and flat add weight to the top. As the document dries in the blotting paper it will also dry flat with little or no warping.
A word of caution: This process can cause much greater damage if rushed and forcibly opened. Take your time. If you get to a point where it doesn’t seem to be working…STOP. Call a conservator.
With the document flattened and dry, you may now want to look to its mending and encapsulation. Handling a document in this weakened state can also cause irreparable damage. Mylar or polyester sheets can encase the document and then careful handling will give you the chance to study the contents of the document.