Fused glass is said to have been discovered about 4,000 years ago by Phoenician sailors who cooked a meal on a beach under the stars. When they moved their pots the next morning, the sand beneath had turned to glass. Art glass fusing virtually disappeared when the Romans developed glass blowing, resurfacing in the 1940s and growing rapidly in the 1990s when the Bullseye Glass company developed a special line of fusible glass. While there are many different kinds of glass, the essential elements are still sand and intense heat.

Fused glass -- also called warm glass and kiln-formed glass -- happens when cut pieces of art glass are fired in a kiln to 1600o F or more. The glass starts out as big sheets of art glass (usually 24" x 36") that I cut by hand with a simple glass cutter. I use my own designs, combining different sizes, shapes, textures and colors of glass in two to six layers. Some glass is clear, some is colored transparent, some is colored opaque, some has an iridescent coating, and some is dichroic glass (see below). When a piece is all put together, it goes into my kiln on a ceramic shelf and the fusing begins.


What makes glass a unique material is that it's always a liquid -- glass is known as "the fourth state of matter" because it has no solid or gaseous state. Even though windows and wine goblets seem to be solid, the glass they're made of is actually a supercooled liquid whose molecules are moving very, very slowly. As the glass heats up in the kiln, its liquid nature becomes visible. At about 1450F, you can see the edges of the cut glass starting to soften and melt. At 1550F, most glass is beginning to actually flow and behaves like syrup (extremely hot syrup!), and as its temperature continues to rise, you can actually see it moving in the kiln.

How hot the kiln gets has a lot to do with how a particular piece of fused glass looks when it's done. Some of my designs use a "tack fuse" --meaning the glass gets hot enough for all the cut pieces to fuse into one solid piece of glass, but the cut pieces still maintain their individual shape and texture. Most of my Desert Glass pieces are tack fused. Other designs, like the Light on Water pieces, are fired to higher temperatures so they reach "full fuse," with the separate pieces losing their angular shape and melting into a softly controlled puddle.

After the glass reaches the right temperature for a particular piece, the cooling process begins. All the glass has to expand and contract at the same rate (i.e., have the same "coefficient of expansion") so that the cut pieces will melt together completely and still be stable when the glass cools again. The glass is cooled very slowly (annealed), and when it's done, the pieces are hand filed. Some pieces are fired more than once, with new layers and elements added in between firings.


I use dichroic glass in much of my work. Dichroic (pronounced dye-KRO-ik) means "two colors" (Greek): dichroic glass reflects one color (i.e., when light bounces off the surface of the glass) and transmits a different color (i.e., when light passes through the glass). A third color is usually visible at an angle. Dichroic glass represents a contribution of the aerospace industry to the art world. (Re-entry tiles on the space shuttle have dichroic coatings.) The technology is based on thin-film physics. Dichroic glass is made in a vacuum chamber, where hot glass is coated with multiple microlayers of metallic oxides (selenium, titanium, manganese and others) that have been vaporized with an electron gun. The transmitted and reflected colors in a particular piece of dichroic glass depend on which metallic oxides were used, and on how many microlayers were applied and in what order.

When you look at a piece of dichroic glass, you see the reflected color. When you hold it up and look through it, you see the transmitted color. If the dichroic coated glass is on an opaque glass background, like the Soul of Blue and Spirit Places pieces on black glass backgrounds, you only see the reflected color -- but you see it with great intensity. If the dichroic coating is on a clear glass background, besides being able to see the colors shift when you look through it, you can look at the sides of the piece and see that there's actually no color in the glass itself -- it's clear glass. The colors you see are physics in action -- the result of the microlayers of metallic oxides, which are colorless themselves, interacting with light.


Is the glass fragile? Does it require special care? The glass is no more fragile than a good drinking glass -- but no less fragile, either. Things that would break a drinking glass will break fused glass, like dropping it on concrete or some other hard surface, striking it hard against another piece of glass, etc. Barring that sort of thing, the pieces should last forever, just like glass beads do. (Glass beads can last for thousands of years -- much longer than we do!)

The glass can be washed gently with clear water or alcohol if it needs cleaning.

There's no paint in the glass, so there's nothing to fade or scratch off. Dichroic glass won't fade or scratch once it's been kiln fired.

Occasionally I get a call from a customer who has done something that chipped or broke their fused glass jewelry. In these cases, I'll fix the piece if I can, and if not, I'll give them a discount on a similar piece.

And remember... wearable art is still art when you're not wearing it! Hang your glass where you can see it betweeen wearings, and the color will give you something every time you pass by.