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Brief History of Borosilicate Glass

Borosilicate glass is a specialized glass known for its exceptional thermal shock resistance, durability, and low thermal expansion. It is primarily used in laboratory equipment, cookware (like Pyrex) and art.

Origins and Invention

Glassmaking dates back thousands of years, but traditional soda-lime-silica glass ( soft glass ) was prone to breaking under sudden temperature changes.

In the 1880s–1890s, German chemist Otto Schott (1851–1935), working with physicist Ernst Abbe, experimented with glass compositions in Jena, Germany. By adding boron oxide (from boric acid) to silica, Schott created a new family of glass with superior heat resistance and chemical stability. He is credited as the inventor of modern borosilicate glass. The glass was commercialized around 1893 under the brand name Duran for laboratory use.

Adoption and Popularization

Early 1900s: Corning Glass Works in the U.S. developed its own borosilicate formulation called Nonex ("non-expansion") for durable railroad lantern lenses.
1915: Corning introduced Pyrex (originally "pie-rex" from a home cooking experiment by Bessie Littleton). It quickly became iconic for ovenware and lab glass in the English-speaking world.
1930s: Borosilicate glass enabled industrial-scale production of glass fibers (fiberglass).

Modern Era

Borosilicate glass (often referred to as Pyrex) revolutionized laboratories, pharmaceuticals, and consumer products due to its ability to withstand rapid temperature shifts without shattering. And, true borosilicate remains the standard for high-performance applications.

Today, it continues to be essential in scientific research, medical devices, high-end lighting, and artistic glassblowing.

Key Properties (why it matters):

Low coefficient of thermal expansion
High resistance to thermal shock
Excellent clarity and durability

Artistic Evolution of Borosilicate Glass

While borosilicate glass originated for scientific and industrial uses in the late 19th and early 20th centuries, its adoption in the arts accelerated in the mid-to-late 20th century. Artists discovered that its low thermal expansion, durability, and workability at the torch (lampworking/flameworking) allowed for larger, more complex sculptures and intricate pieces that were difficult or impossible with traditional soda-lime glass. By the 1980s and 1990s, borosilicate became a favorite among glass artists for extreme precision and detail.

Expanding Color Palette

Early artistic borosilicate work was mostly clear or limited in color. A major breakthrough came in the 1980s when Paul Trautman developed the first commercial colored borosilicate rods (initially through Northstar Glassworks, later Trautman Art Glass). This dramatically expanded the artistic possibilities, introducing vibrant opaques, transparents, striking colors (that change with heat or annealing), reactive hues, and specialty effects like UV-reactive, metallic, or "slyme" variations. Today’s palette exceeds 100 colors from various makers, featuring jewel tones, pastels, shimmering effects, and complex blends. These advancements, combined with techniques like latticino, murrine, and linework, have made borosilicate a vibrant medium for contemporary glass art.

Borosilicate Flameworking and the Modern Studio Glass Movement

Borosilicate flameworking (also known as lampworking or torchworking) has become the defining technique of the contemporary studio glass art movement because it democratized glassmaking. Unlike traditional hot-glass studio practices that require massive furnaces, high-temperature glory holes, and large teams, borosilicate artists can create in smaller, more accessible home or private studios using handheld torches. Its superior thermal shock resistance allows for greater complexity, larger scales, and intricate detailing without constant annealing risks.

This accessibility sparked an explosion of independent artists, makers, and hobbyists since the 1980s–1990s, fueled by innovations in colored glass rods. Today, it represents a dynamic, grassroots side of glass art—encompassing everything from functional pieces and scientific sculptures to elaborate marbles, and large installations. For the broader glass art world, it has expanded participation, fostered innovation in color and technique, and created a vibrant parallel ecosystem alongside blown and cast glass traditions, making glass art more diverse, inclusive, and globally influential than ever before.

Dichroic Glass: History and Description

Dichroic glass is a high-tech, color-shifting material that appears as two or more different colors depending on the angle of light and whether it is viewed in reflection or transmission. Modern dichroic glass is created by applying ultra-thin layers (often 30–50) of metal oxides (such as titanium, silicon, or magnesium) onto clear glass through a vacuum deposition process. This precise coating causes light interference, producing vibrant, iridescent effects that change dramatically with viewing angle.

The modern version was developed in the 1950s–1960s by NASA and contractors for aerospace optical filters to protect against intense solar radiation. In the early 1970s, artists (including former aerospace engineers like Murry Schwartz) began adapting the material for studio glass art. Since then, dichroic glass has become a staple in contemporary glass art, used in jewelry, sculptures, fused glass pieces, and installations for its mesmerizing, gem-like color shifts.

Adam working in his Studio