What Is Dichroic Glass? How It Works and How I Use It in My Art.

One of the things that fascinates people about my glass artwork is the way its colors seem to change as they move around a piece. That captivating effect comes from dichroic glass, a material that reflects one color of light while transmitting another. I use dichroic glass to introduce unexpected color, depth, and visual movement into my work.

Dichroic glass

What does "dichroic" mean?

The word comes from the Greek for "two colors." Dichroic glass transmits one color of light and reflects a different one, so you see two colors at once, and they change as you move or as the lighting shifts.

"The Beginning" by Deborah Ellington

How is dichroic glass made?

Dichroic glass begins as ordinary glass that is transformed through a specialized coating process developed by Gerald (Jerry) Sandberg, drawing on his experience in scientific optics at NASA.

I purchase my glass from CBS-Coatings by Sandberg in Los Angeles, California. Curious about how this remarkable material is made, I visited the facility, where Samantha showed me the kilns and the stainless-steel stencils used to create some of the glass’s patterns.

The process takes place inside a vacuum chamber, where materials are vaporized and deposited onto the glass in multiple, ultra-thin layers. These coatings consist of silica (silicon dioxide) and zirconia (zirconium dioxide). As Samantha explained, “Our colors have as many as 30 layers of these materials, yet the thickness of the total coating is approximately 35 millionths of an inch.”

These microscopic layers interact with light, reflecting certain wavelengths while allowing others to pass through. The number and thickness of the layers determine the colors produced, giving dichroic glass its distinctive color shifts and luminous effects.

Dichroic Ring by Deborah Ellington

Why does the color change?

Dichroic glass is a form of thin-film interference, the same phenomenon behind soap bubbles and oil slicks. As your viewing angle changes, light travels a different path through the layers, so different wavelengths are reflected.

Detail showing dichroic from "The Beginning"

See dichroic glass in person.

Photos only capture part of the effect. If you're in the Houston area, visit my studio at Silver Street Studios, 324, to experience for yourself the beauty of dichroic glass.