Due to the fact that many archive collections from the historical resources include various seals, the restorer’s workshop of Cieszyn’s Historical Library launched the research on methods to be used for securing the wax and wafer seals based on the sealing wax, standard wax or other type of putty.
Unfortunately, the material with seals gets brittle to finally break up as a result of particle refinement. The seals are attacked by microorganisms very often as well.
Conservation includes structural reinforcement of the seals with special resins. Selection of an optimum concentration of such resin is not an easy task; it requires application of different agents and many trials, as some of them are insufficient, others cause excess polishing of seal surfaces, etc. However, before a good resin is verified for use, the seal surface should be cleaned with various restoring soaps –using soft brushes, cotton balls, needles, pincers… The resin can be injected into missing areas or applied with a brush, often on a vacuum table, which sucks the resin and makes it adhere to the seal. If the reduced areas are extensive, the process includes adding of so-called securing strips, which are made of wax and protect seal sections against mechanical damage. Like in the case of manuscripts, such reductions are not processed.
An additional obstacle is the fact that the seals are usually applied directly on the paper, which requires extreme care while sheet restoration. Seals are found mainly on manuscripts and sometimes on printed documents. An interesting fact is that seals made of regular wax instead of sealing wax are preserved better. As for the sealing putty (or flour-based pulp), the restorers face have to face the problem of limiting the use of water in processing. On the other hand, these putty seals are very often the most attractive in terms of the form, especially if provided with decorating cuts around the rims.