The Gipsformerei is part of the Staatliche Museen zu Berlin and since about 1820 it has been producing casts of original works not only of the Berlin museums. Its origin is due to the need of museums and other scientific institutions to have exact original casts of important sculptural works of art.
While the art collections were evacuated for safekeeping at the beginning of the war, the moulds and models of the Gipsformerei stayed in their Charlottenburg home. Unlike the museum collections, the holdings of the Gipsformerei survived the war intact. If the Zentralarchiv (central archives) is the historical, document-based memory of the Berlin Museums, then the Gipsformerei can be considered their three-dimensional memory. Many of the plaster casts produced specifically for the exhibition "The Lost Museum" provide, for the first time since 1939, a vivid impression of major works that are missing from the Skulpturensammlung.
Thomas Schelper, moulder in the Gipsformerei, on the technique of plaster casting: “One of the most wellknown and beloved pieces that we possess is the Laocoon group. The original is in the Vatican. The cast had already entered into the inventory at the beginning of the 19th century. The mould is taken in separate sections. After drying, these must be soaked in a wax bath. This makes the mould very resistant; it can last for centuries. For the production of such a mould, one needs a great deal of time. For a mould the size of the Laocoon, an experienced moulder needs at least 3 to 4 weeks."
Of course, some objects are problematic, for example when they are polychrome. In the case of a sensitive material like wood, the objects were wrapped with thin tin foil, and the cast was made over this tin foil.
The release compounds that are used, or were used, were at one time soap, for example curd soap or soft soap, or even wax mixtures that were specially prepared by melting beeswax and thinning it with turpentine. In the past, those were the most popular compounds.