The electrotyping or galvanoplasty process is an artistic method that creates metal facsimiles of an object through an electrochemical means. Most notably, its applications include creating metal replicas of artistic and historical artifacts, as well as plates for letterpress printing. Please note that “electrotyping” and “galvanoplasty” are often used interchangeably to describe the same method, but will be referred to as galvanoplasty moving forward. Here, we break down the galvanoplasty process, discuss its historical significance, and explain the difference between this and the similar “electroplating” artistic method.
The galvanoplasty process is electrochemical in that the ions of one type of metal accumulate on the exterior of another under the direct current of an electrolyte. This is done by having a mold of the original piece you are trying to copy fully submerged in an electrolyte solution (metal salt) and then connected to a cathode (the negative pole of the direct current source). The type of metal you want deposited (i.e. copper) is then also put into the electrolyte bath and then connected to the anode (the positive pole of the direct current source). Once the electric current is live, it then dissolves the metal that is located at the cathode, which thereby converts that metal’s atoms into ions. Once the metal ions are created, the anode then attracts them to where they start to gather in the form of a metal coating on the mold.
The galvanoplasty process is done to create a galvanoplastic bas-relief— bas-relief traditionally being a technique where an artist sculpts into a 2D plane that would then allow a 3D image to emerge and be viewed from all angles with little distortion, as the 2D plane is chipped away at to provide different levels instead of a flat plane. However, in this case, the 3D nature of the piece is created by the metal ions sticking to the mold of the original work. The mold is coated with an electrically conductive paste, as the silicone itself would not facilitate an electric current. This is normally done with a graphite powder. The electrically conductive paste is applied as a very thin layer, in order to not accidentally change the shape of the piece of which you are trying to create a replica. It can be difficult to maintain the artistic vision of the original or mold, while still being sure the electrically conductive coating fully engulfs the silicone, as an incomplete coating would create an incorrect replica on the other end of the process.
In order to have a solid replica done in the bas-relief style, it is necessary to obtain a certain thickness of metal ions that accumulate on the silicone. The measurement of the coating is directly correlated to how long the electrotyping process is performed; the longer it goes on for, the thicker the result. For a solid piece of metal, electrotyping needs to be performed for at least one full day. In addition to the time this process requires, it is important to monitor other variables as well that might influence what the final product looks like. These include the temperature, the amperage, and the ratio of the electrolyte concentration.
The following vide from Victoria and Albert Museum offers a glimpse of the electrotyping/galvanoplasty process and how is relief art created through it:
Once you have achieved the desired thickness in the galvanoplasty process and the bas-relief is successfully accomplished, it is important to note that there are still other steps in the process that are needed for the piece to be in its final shape.
Next, you will want to remove the newly created metal piece from the mold once it is completely finished and hardened, followed by making sure your new metal piece is clean of all of the electrolyte solution or any other possible debris. A simple toothbrush is a great tool to help accomplish this check. You can also use an ultrasonic cleaner, or even good old vinegar solution to then soak the piece in.
After removing the mold and cleaning the piece, you will want to add the patina. A patina is created through a chemical reaction between the metal, high temperatures, and acidic chemicals that oxide the surface of the piece you have created. The surface is usually heated to temperatures from 450 to 475 degrees Fahrenheit, at which point the chemicals are added by bristle brushes, airbrushes, spatter guns, or spray bottles. The exact color of the piece can be customized based on the types of chemicals used, and can range from golds to reds, to greens, or to blues. Then, a sealant is applied to seal in the patina, followed by a wax to finish it off.
Finally, if the piece does not stand alone by itself (i.e. it is not a sculpture, or letter plate but rather is a piece to be framed), pick out a frame that fits where you will personally be placing the artwork, or with what the client has requested. Now you have a work created by the galvanoplasty process!
Galvanoplasty was originally invented by Moritz von Jacobi in 1838 in Russia. Historically, it was helpful in both printing and in distributing copies of valuable metal artifacts to more provincial cultural institutions at a time when the dissemination of information through photographic and technological means was not as practical as it is today.
In terms of printing, galvanoplasty was popular for creating plates for letterpress printing in the 19th century. This was an evolution from the previously used stereotyping method that involved metal casting. Both of these methods–galvanoplasty and stereotyping–survived until the end of the 20th century, when offset printing became the norm.
As for metal replicas for artistic and historical purposes, in the Victorian era in the United Kingdom, the South Kensington Museum of London (which is now known as the famed Victoria and Albert Museum) would purposefully create galvanoplasties of historically important artifacts so that schools, libraries, and museums outside of London would have a sense of what such pieces looked and felt like. This type of work reached a pinnacle in 1867 when 15 European nations signed the Convention for the International Exchange of Reproductions of Works of Art initiative to help the exchange of artistic and historic information. This then allowed manufacturers, such as Elkington & Son and Franchi & Son, to recreate important artifacts in nations such as France, Germany, Russia, and England. This idea even grew outside of Europe, such in the United States as when Tiffany & Co. took to creating galvanoplasties in the same manner.
Similar Artistic Processes
It is also helpful to point out that a very similar sounding artistic method to electrotyping (galvanoplasty), known as “electroplating”, is not actually synonymous with galvanoplasty. Electroplating involves creating a thin metallic layer on an already existing object, while galvanoplasty results in a metal object that is completely freestanding and of your desired thickness.
Electroplating is primarily for the purpose of changing the surface property of an object for reasons such as for wear resistance, abrasion resistance, corrosion protection, aesthetic purposes, or lubricity. An analogy to help you better visualize and understand the difference between the two would be how a sculpture or piece of jewelry might be either gold plated, where the inside of the piece is a different material while gold plates the outside visible parts (i.e. this would be akin to electroplating), or, be solid gold in and of itself (i.e. this would be like galvanoplasty).
Together, this information should help explain the complex process involved in creating a piece with galvanoplasty (electrotyping), along with the historical significance of the process and how it differs from the similarly named electroplating, allowing you to embark on your very own galvanoplasty project.