Most contemporary fusing methods involve stacking, or layering thin sheets of glass, often using different colors to create patterns or simple images. The stack is then placed inside the kiln (which is almost always electric, but can be heated by gas or wood) and then heated through a series of ramps (rapid heating cycles) and soaks (holding the temperature at a specific point) until the separate pieces begin to bond together. The longer the kiln is held at the maximum temperature the more thoroughly the stack will fuse, eventually softening and rounding the edges of the original shape. Once the desired effect has been achieved at the maximum desired temperature, the kiln temperature will be brought down quickly through the temperature range of 815 °C (1,499 °F) to 573 °C (1,063 °F) in order to avoid devitrification. It is then allowed to cool slowly over a specified time, soaking at specified temperature ranges which are essential to the annealing process. This prevents uneven cooling and breakage and produces a strong finished product.
This cooling takes place normally for a period of 10–12 hours in 3 stages.
The first stage- the rapid cool period is meant to place the glass into the upper end of the annealing range 516 °C (961 °F). The second stage- the anneal soak at 516 °C (961 °F) is meant to equalize the temperature at the core and the surface of the glass at 516 °C (961 °F) relieving the stress between those areas. The last stage, once all areas have had time to reach a consistent temperature, is the final journey to room temperature. The kiln is slowly brought down over the course of 2 hours to 371 °C (700 °F), soaked for 2 hours at 371 °C (700 °F), down again to 260 °C (500 °F) which ends the firing schedule. The glass will remain in the unopened kiln until the pyrometer reads room temperature.
Note that these temperatures are not hard and fast rules. Depending on the kiln, the size of the project, the number of layers, the desired finished look, and even the brand of glass, ramp and soak temperatures and times may vary.
Fused glass is a term used to describe glass that has been fired (heat-processed) in a kiln at a range of high temperatures from 593 °C (1,099 °F) to 816 °C (1,501 °F). There are 3 main distinctions for temperature application and the resulting effect on the glass.
Firing in the lower ranges of these temperatures 593–677 °C (1099–1251 °F) is called slumping. Firing in the middle ranges of these temperatures 677–732 °C (1251–1350 °F) is considered “tack fusing”. Firing the glass at the higher spectrum of this range 732–816 °C (1350–1501 °F) is a “full fuse”.
All of these techniques can be applied to one glass work in separate firings to add depth, relief and shape.
While the precise origins of glass fusing techniques are not known with certainty, there is archeological evidence that the Egyptians were familiar with rudimentary techniques ca. 2000 BCE. Although this date is generally accepted by all researchers, some historians argue that the earliest fusing techniques were first developed by the Romans, who were much more prolific glassworkers. Fusing was the primary method of making small glass objects for approximately 2,000 years, until the development of the glass blowpipe.
Glassblowing largely supplanted fusing due to its greater efficiency and utility.
While glass working in general enjoyed a revival during the Renaissance, fusing was largely ignored during this period as well. Fusing began to regain popularity in the early part of the 20th century, particularly in the U.S. during the 1960s. Modern glass fusing is a widespread hobby but the technique is also gaining popularity in the world of fine art.
Exhibition in 2014 to Showcase Museum’s Outstanding Lalique Collection
Corning, NY— The Corning Museum of Glass has received an important collection of approximately 400 objects by the famous luxury glassmaker René Lalique (French, 1860–1945), from Maryland collectors Stanford and Elaine Steppa. Combined with the Museum’s existing holdings of glass objects and wax and plaster models by Lalique, the Glenn and Mary Lou Utt Archive related to Lalique designs for the fragrance industry, the drawings and photographs housed in the Rakow Research Library, the gift of the Steppa Collection makes the Museum a preeminent international repository for the study of Lalique glass. The Museum will showcase its Lalique collection in a major exhibition to be held in 2014.
The Steppa Collection encompasses a wide range of Lalique’s best-known works including perfume bottles and pressed-glass vases, as well as ashtrays, boxes, clocks, car mascots, lamps, statuettes, inkwells and blotters, and tableware dating primarily to the years between 1912 and 1936. It joins the Museum’s current holdings of 200 objects by Lalique, as well as more than 2,000 photographs and design drawings in the Museum’s public-access Rakow Research Library.
“This gift significantly broadens our Lalique collection, providing a fantastic overview of the wide range of luxury objects that Lalique’s factory produced during his lifetime,” says curator of modern glass Tina Oldknow. “We look forward to showcasing the full breadth of Lalique’s artistic output in our 2014 exhibition.”
A highlight of the donated collection is the heavy cire perdue vase called Martins-Pecheurs sur fond de roseaux (Kingfishers on a background of reeds) [2011.3.188], created in 1930. Cire perdue, or lost wax, is a technique commonly used for casting bronze, and it was mastered by Lalique for creating glass objects. The Museum’s collection contains several original wax molds from the Lalique glassworks, which would have been used to create other unique cire perdue glass vessels, including a mold with the same kingfisher design as the Steppa vase. Other significant objects include the remarkable clock, Le Jour et la nuit (Day and night) [2011.3.276], and the iconic Art Deco statuette of a dancer, Suzanne [2011.3.256].
Lalique embraced the idea of the Gesamtkunstwerk, or total work of art. This concept was reflected in most Art Nouveau interiors, where a single motif or theme might be present on all of the furnishings of a room. Lalique began his career as an innovative Art Nouveau jeweler who incorporated glass into many of his bijouterie creations. The flacons that Lalique designed for well-known parfumiers, such as François Coty, helped to elevate the status of perfume, and propelled French perfume into international luxury markets.