About Warm Glass

A Multi-Step Process

Red Accents PlateWarm glass is about the reaction of fusible art glass as it is heated to kiln-forming temperatures of up to 1500⁰(F). While that reaction is generally predictable, the varying properties of the specific glass and the exact firing conditions make each firing unique. This 9 ½” square plate is made from more than 40 pieces of 4 different kinds of glass. What you see here is the result of 4 separate kiln firings taking over 50 hours of firing time.




Starting with a Pattern Bar

PatternBarThe organic design of color in the center of the plate is created from a pattern bar. The bar itself is approximately 30 strips of glass in three colors (black, white, and red) that are fused together to form a 2” x 6” x 1” glass brick. Firing time: 16 hours.



Cold Working the Pattern Bar

ColdWorkIt is the profile of the bar that is of interest, so the bar is cut into 10mm slices using a diamond bladed tile saw. Once the design layout of the slices is determined, a glass grinder is used to square and smooth the edges of each slice so they fit together nicely in the center of the plate. Finally, a series diamond pads are used to smooth the surfaces of each slice.





Making the Base Plate

The second firing creates the “blank” or base plate. To complete the plate, three layers of glass (clear, black, red) are wrapped around the organic color design. Firing time: 14.5 hours.Base Plate

Fire Polish

Fire PolishThe base plate is fired with the top (clear) side down. After some additional cold working to smooth and round the edges of the base plate, it is fired again face up “fire” polishing it to a glossy finish. Firing time: 11.5 hours.





Forming the Plate

SlumpThe fourth and final firing is to shape the plate by slumping it into a hardened clay mold. Firing time: 11 hours.





The Final Product!

Final Product




About Stained Glass - Copper Foil Technique

Designing a Panel

Three Tulips Pattern It all starts with a client’s idea. This Three Tulip panel is designed to fit into an octagonal window and will be lighted from behind. Our designs often start as rough sketches and then are reviewed for colors and size and then finalized with the client. 



Selecting the Color Palette


Once we’ve settled on the design the next step is to colorize it and begin selecting the specific glass. The tulips will be yellow, the leaves green, with a darker green for the shadows, and darker still for the stems. For the basket will have a weave effect so dark brown will be mixed with a lighter cream color. The sky is blue with some white streaks. That creates our color palette


 Building the Panel

WovenBasketLike anything else stained glass panels are built a piece at a time. This design calls for 60 pieces. Each one is carefully chosen from specific areas of the sheet glass according to color variation, grain and or texture in the glass. The piece is then cut, shaped to fit as need with a grinder or other diamond tools, and then wrapper in copper foil. I tend to do this for small sections at a time to ensure a proper fit. Here, the pieces for the woven basket have been laid out on the glass sheets and then fitted into the design:

Construction continues incrementally until all the pieces in the design fit together properly. 

 Build Increments

Completing Construction

FramingOnce we are satisfied with the fit of all the pieces they are joined by soldering along the copper foil lines. A frame of zinc came is then added and optionally, a patina is applied to give the panel an aged look.



The Final Product!

Final Panel










I Have This Mold...

After starting to work with glass it did not take long realize that glass cutters are to glass artists what putters are to golfers. There is always one a little bit better one just lurking around the corner ready to snatch up your credit card. For glass fusers, slumping molds seem to hold the same allure.

Meet our latest acquisition. A 12 inch round organic bowl about 3 inches deep with a nice wavy lip all the way around. Better yet it was on sale at a really good price! My credit card could not pass it up.


Now what to do with it…

First a base plate of two circles of glass fully fused together. In this case a transparent blue topaz with a clear sheet and a little clear powder in between to reduce bubbles. That gives us a pretty blue plate, but it’s also a little bit boring.


So next we dress it up a bit with some design elements:

  • First a slightly smaller circle of white glass that is cut into quarters along curved lines. Because it is a smaller circle the white pieces can be spread out a bit when placed on the base plate, leaving the blue to show through. These are kept in place with a couple dabs of clear Elmer’s Glue so we can continue to work on the plate.
  • Next a mixture of white and black frit is added to the center of the plate in circular pattern that will become the bottom of the bowl.
  • Finally, color is added to the white glass using pastel green and yellow opalescent frit, adding a charcoal gray line in between.  A light layer of hair spray keeps all the frit in place while we move the whole thing into the kiln.

Here it is all ready to fire for a second time. This will be a contour fuse so the edges of the white glass and the texture of the frit remain. (The glue and hair spray burn off between 500 and 700 degrees leaving no trace, but it is a bit smelly!)


Finally, a third firing to slump the plate into the latest acquisition and we have new bowl!

BluePlateSlump  Image 1


Pattern Bars Rule!

I've been taken with pattern bars over the last few weeks and am finding that it is a great way to add a flourish of color to a larger work. The bars are made by fusing multiple pieces of glass into essentially a glass brick. The individual pieces of glass can be completely random or placed in some type of design of their own.

Here are the latest two all set to be fired.The one on the left is strips of equal length arranged in a pattern -- see the side profile. The one on the right is just broken pieces of glass of various sizes and colors. It turns out that pattern bars are a great way to use up some of that scrap glass.

BarsReadytoFire Side Profile



After firing, the bars look like this. Both bars are 145mm x 50mm x 27mm.

FiredBars  FiredBarProfile 

The next step is to the slice the bars into 10mm strips with a wet saw and decide how to lay them out to incorporate as a design element in another work..


I've already incorporated the random colors bar into a new work. Can you see the pattern bar slices in it?

Image 1