Definitons

CMoG has published a book by the late David Whitehouse, Glass, A Pocket Dictionary Used to Describe Glass and Glassmaking. The CMoG website, cmog.org under the tab RESEARCH contains a Glass Dictionary based on David Whitehouse’s book. From time to time, we’ll be republishing parts of the dictionary that may be relevant to our Steuben readers.

A Definition from CMoG’s Glass Dictionary

Acid Etching

The process of etching the surface of glass with hydrofluoric acid. Acid-etched decoration is produced by covering the glass with an acid-resistant substance such as wax, through which the design is scratched. The object is then immersed in hydrofluoric acid, or a mixture of dilute hydrofluoric acid and potassium fluoride is applied to etch the exposed areas of glass. Acid etching was first developed on a commercial scale by Richardson’s of Stourbridge, England, which registered a patent in 1857. An effect superficially similar to weathering can be obtained by exposing glass to fumes of hydrofluoric acid to make an allover matte surface.

Acid Etching as Described on the Carder Steuben Club Website

Frederick Carder used several different decorating techniques on his Steuben glass. One of the more important techniques is acid etching. Acid etched patterns could be made on cased glass which made a contrasting pattern on the glass or the pattern could be made on a single color. The acid etched process is described beginning on page 112 of The Glass of Fredrick Carder by Paul Gardner. Basically it involved engraving a pattern on a flat glass or metal plate, filling the pattern with wax and transferring the wax pattern to the object to be etched using paper as a transfer medium. When the object was placed in a hydrofluoric acid bath the glass that was not protected by the wax was removed. Occasionally a piece will be found where it appears that the acid bath did not completely remove the top layer of glass. An example of this is found in Figure 10.34 in Tom Dimitroff’s book, Frederick Carder and Steuben Glass.

Carder used more than 235 patterns for his acid etching. These patterns were applied to any number of the different shapes. The patterns on cased glass often took one of two forms. The first was just a simple pattern and was produced with one emersion in the acid bath. The second was what is now called double etched. The first etch was the same as the single etch described above. After the first etch a new small background pattern was applied and the glass went though a second etch producing a more complex pattern.

When the acid etched process was applied to a single color glass the pattern could be etched much more deeply than was usually done with a cased glass. This process was often called sculptured or carved. There is now a certain amount of confusion concerning these two terms. The existing factory records use these terms as descriptive terms for other patterns. An example is Sculptured Carrara which was a deeply etched pattern in a white glass that resembled Carrara marble. Now, these two terms have taken on other meanings and are often used as pattern names themselves.

Shape: 6456

Form: Vase

Color: Carrara Marble

Type: Acid Etched

Etching: Carrara