Electrotyping (also galvanoplasty) is a chemical method for forming metal parts that exactly reproduce a model.
The method was invented by a Prussian engineer Moritz von Jacobi in Russia in 1838, and was immediately adopted for applications in printing and several other fields.
The mold's surface is made electrically conducting by coating it very thinly with fine graphite powder or paint.
[1][4] Nineteenth-century accounts often credited Thomas Spencer or C. J. Jordan with the invention in England, or Joseph Alexander Adams in the United States; Heinrich in particular gave a thorough account of the controversies surrounding the crediting of the invention, along with a short biography of Jacobi, in an article honoring the centennial of electrotyping in 1938.
Initially, electrotyping was used to make copper reproductions of engraved metal plates or wooden carvings, which were used to print artwork.
[1] Electrotyping was also used to produce entire printing plates directly from the formes composed from movable type and illustrations.
In this application, electrotyping was a higher quality but more costly alternative to stereotyping, which involved casting of type metal into a mold prepared from the forme.
Both methods yielded plates that could be preserved in case of future needs, for example in the printing of novels and other books of unpredictable popularity.
These generators supplanted the whole rooms of chemical batteries (Smee cells) that were previously used to provide electricity for electrotyping.
Electrotyping was used for general-purpose type manufacture in the nineteenth century, but was a somewhat disreputable process, leading to some typefounders disdaining it (or at least claiming to).
Stephenson Blake's solution was to squash type slightly in a press or file it down to broaden it before putting it into the electrotype bath.
One of the earliest documented large-scale (1.67 metres (5.5 ft)) electrotype sculptures was John Evan Thomas's Death of Tewdric Mawr, King of Gwent (1849).
[18] Among the most spectacular early examples are Josef Hermann's twelve angels (1858) at the base of the cupola of Saint Isaac's Cathedral in St. Petersburg, Russia (see photograph A below).
As described by Théophile Gautier in 1867, "They are twenty-one feet high, and were made by the galvanoplastic process in four pieces, whose welding together is invisible.
"[19] Other important sculptures followed; David A. Scott has written, "Some extremely important commissions were made in electrotypes, such as the "bronzes" that adorn the Opera, Paris, and the 320 cm high statue of Prince Albert and four accompanying figures, erected behind the Albert Hall in London as a memorial to the Great Exhibition of 1851.
"[20] The Palais Garnier in Paris (the Opera) has two 7.5 meter tall sculptures above the main facade; the building was completed in 1869 (see photograph C below).
The most celebrated may be their copy of the Jerningham wine cooler, which is a spectacular silverwork made in England in 1735 that has long been in the collection of the Hermitage Museum in Russia.
[25] Memorials in German cemeteries from this era often incorporated electroptyped statues from models that had been commissioned by WMF from well-known sculptors (see photograph F below).
[4] One example is the full-sized copper electrotype (1911) of Ernst Rietschel's 1857 bronze for the Goethe–Schiller Monument in Weimar, Germany, which is about 3.5 metres (11 ft) tall (see photograph at right).
Many sculptors have experimented with the technique of electrotyping a plaster form that remains as the core of the finished sculpture (Kerngalvanoplastik).