Q. What is the history of glass slumping and fusing?

Image: Ti. Gyorgy Buczko (Hungarian, b. 1950), artist. CMoG 95.3.23.

Hello! Thank you for your question.

Definitions

The online Glass Dictionary includes definitions for "fusing" and "slumping" that might be useful for those of you who are new to the subject.

Fusing: "(1) The process of founding or melting the batch; (2) heating pieces of glass in a kiln or furnace until they bond (see Casting and Kiln forming); (3) heating enameled glasses until the enamel bonds with the surface of the object."

Slumping: "The process of reheating a blank until it becomes soft and gradually flows under its own weight over or into a former mold and eventually assumes the shape of the mold. Soda-lime glass becomes soft at about 1110°F (600°C). Slumping is also known as sagging."

History

• In the book Five Thousand Years of Glass, Hugh Tait describes evidence of these glass-forming techniques found in ancient Syria, Palestine, and Egypt.
• Boyce Lundstrom, in Kiln Firing Glass, asserts that ancient Romans utilized the methods as well.
• Keith Cummings provides historical and technical background in A History of Glassforming.

You might also be interested in the article, "The Ancient History of Warm Glass," by Joanne Stuhr, which appeared in the 1997 Glass Art Society Journal (pp. 24-26).

Techniques

​The Rakow Research Library has prepared a couple of research guides that might be helpful in researching fusing and slumping techniques:

• Kilnworking (includes a page on Fusing & Slumping)
• Molds and Moldmaking (includes a page on Kilncasting)

The Warm Glass Gallery and Studio (Clemmons, NC) includes "The Basic Fusing and Slumping Process" on its website,which may provide additional information.

Borrowing Library Materials

If you wish to borrow copies of library items, please contact your local library. The Rakow Research Library will lend designated books from its collection and will send copies of articles requested by other libraries. Your library can request items through the OCLC WorldShare Interlibrary Loan (ILL) system or by direct request through email at ill@cmog.org. For more information, please see our ILL policies and procedures.

Browse Objects from the Museum Collection

See some examples of fusing and slumping from The Corning Museum of Glass collection.

Take Classes at The Studio

The Studio at The Corning Museum of Glass offers classes all year round, some of which might be of interest to you.

Please don't hesitate to ask us your glass-related questions in the future!