Description
This is a technique to make the surface matt with a satin finish, or even deeply etch it by following a decorative motif, even on very thin vitreous walls. It was experimented in the 17th century but applied with continuity from the beginning of the 19th century.
It is a technique based on the use of hydrofluoric acid, which is the only acid that dissolves glass in a cold state, in a wide variety of mixtures which can attack the glass in a more or less drastic manner.
If we want to obtain an etched decorative motif, the parts not to be touched must be covered with wax or other materials which are acid resistant, then the object is immersed in the acid so that it can corrode the non-protected areas. With particular tools, we can obtain etchings at various depths, using successive phases of acid baths.
One of the variants is the Corroded technique.