This is the third article in a three-part series about the most important light-managing medium, glass. In this final installment, design ideas involving glass and light are reviewed.

When seeking to provide a really "special effect," not every design must involve hundreds of thousands of dollars to be "effect"-ive. Some pretty basic and affordable lighting systems can be used to make artful and appealing designs that achieve effects unattainable using just shape, pigment, and texture—just add glass.


At the United Air Lines tunnel (top) at O'Hare International Airport, Chicago, the walls appear to "float" in front of a blurred scene of dissolving color and light gradients. At GE's Lighting and Electrical Institute dining room at Nela Park, Cleveland (middle top, middle, and above), a channel acrylic wall with embedded reflectors was installed, front-lighted with video projectors, front washlights, and with a depth-producing backlight color box. In part two of this series, this effect was called an indirect light box (see figure 1). The glazing must be at least lightly textured; lightly etched glass or almost-transparent acrylic is ideal. The interior of the box can be fairly shallow, with the depth ideally about a quarter of the height of the glazing. The back wall and a portion of the floor are painted in a pattern that is intended to be diffused. In other words, imagine a pixilated image viewed through a diffuser; the image will be pleasantly blurred, enough to soften the edges and make the image whole again. The sense of depth can be exaggerated if the wall is painted cool colors or if the interior lighting is a high color-temperature or a saturated cool color such as blue or turquoise.My all-time favorite use of this technique is the United Air Lines tunnel at O'Hare International Airport in Chicago. The walls appear to be floating in front of a blurred scene of dissolving color and light gradients. A volume that otherwise would serve as a utility chase ends up creating a magical environment. I have been traveling through this tunnel for almost 20 years, and this feature never loses its appeal, a lot to be said for some glass, paint, and striplights. I stole the concept for the Jim H. McClung Lighting Center at Acuity Brands Lighting in Conyers, Georgia, a 10-year old installation that also is aging well.


While it may seem simple, the idea of a large light box is still a very useful tool for modern design. At Light+Building 2004, Zumtobel used light boxes to create a Mondrian-like pattern of color-changing walls. While we may think of LED-based RGB systems for this design, in fact the T5HO lamp in primary colors is the best way to make this work, especially with a large enough box.

The real challenge of this design is to make each panel appear almost perfectly illuminated all the way to the edge. Finely detailed acrylic is probably the best way to do this, using the diffusing quality to carry light over a thin box edge. Stretched polymer sheet produces a similar result. If the box is deep enough, three prime-color fluorescent lamps with dimming ballasts and a suitable controller can turn a simple box into a colored light system of almost endless variety and subtlety.

Movement and Sparkle (without actual movement)

Random sparkle is magical. A simple way to create this effect is to use tungsten bud lights or LEDs in a grid, fired to give the sense of random flashing. We have been doing this detail for decades, and it still works. But in current design, it is a bit too simplistic and, well, basic. Architects and interior designers today will want more movement and randomness and a diminished appearance of being a lighting effect.

Glazing products with embedded mirrors in random locations cause little tiny reflections or sparkle. Current products employ a vast array of tiny mirror elements at varying angles to catch light and sparkle as often as possible. The challenge is how to create what appears to be random movement.

The secret of this design is the use of a moving light projector on the material at an appropriate angle. What better than a simple video projector? Fed with a constant stream of comparatively random video, even I Love Lucy will turn a wall into a seemingly endless stream of oscillation and movement.


A basic theatrical technique is using color temperature to emphasize depth. Warmer colors come forward and cool colors recede. Other than using holography, depth is almost impossible to create in two dimensions. In the theater, a scrim (fine white screen) can be used for the foreground; in architecture, using glazing and a little physical depth, a great illusion can be created. The key is to wash the glazing with a gradient of light so the light on the glazing dies off and permits viewing through to the wash on the surface behind.

An example of a dichroic glass block (above). In a 3D dissolving light box, figure 1 (below), painted patterns on the back wall can be seen through the acrylic but the edges are blurred, creating a dissolving effect. The wash on the front panel appears in the foreground like a scrim and the back wall fades away. This effect can also be used without a back wall. RANDOM COLOR

Dichroism is fascinating, an other-worldly effect that seems to defy common sense. Its greatest quality is the saturation and depth of color, and many enjoy its color variability as the viewing angle changes. Imagine what happens if dichroism is applied to uneven glass surfaces—a glass block with one surface coated in dichroic, for example. Use it in a wall, and by day light will pass through the coating's basic color. By night, however, it will become a mirror of interior light, with wavy blends of color that move and change with the viewing angle. In other words, the color from it varies tremendously as conditions in the space evolve. Most importantly, it is a genuine lighting effect that cannot be created any other way. In addition to coating glass block, it is possible to apply dichroic coatings to just about any glass up to about 5 square feet in size, and the surface does not have to be flat.


In many ways, these ideas are not new. Stained glass has been used for centuries, and since electric lighting, we are able to give glass an appealing night quality as well.

But I happen to believe that sustainable design will demand that interior lighting will rely increasingly on daylight, and not only will we use more glass but we will want to do more with it. Using ideas discussed in this three-part series will permit daylighting that is more than just windows, with the added possibility of an electric lighting alternative that provides an interesting and artful nighttime character. Look at glazing as a new opportunity for lighting design where the changing light of day is used as part of a design in which electric lighting is only part of the solution.


Part One

Part Two