The Final Result
Here is the final piece, with the carved frit sheet in front, and a colorful fused sheet backing it up. Please continue on to the gallery to see other examples of this technique, including multi-color frit carvings and hand colored pieces with traditional stained glass paints. If you are wondering if your photo can be converted to a custom carved glass creation, the answer is… YES!
There are several ways to add color to the final piece. Different color frits can be added and carved/fired again. Glass paints, of the type that have been used for centuries in church windows can also be employed. My favorite method, due to the large palette of colors and the deep color saturation that is possible, is to back the carved piece with a fused background layer of cut art glass sheets. Shown here is a fused sheet of brightly colored glass, ready to serve as a backing sheet for the carved frit front sheet.
The Interim Result
The fired glass plate feels like an embossing, in the sense that it has varying heights of fused glass on its surface. In backlight, the photographic yet painterly effect of this process can be seen. In this case, the photo is represented in a single color value…black. But the different heights of black are seen as shades of grey.
Firing in a Kiln
The carved glass powder and substrate glass sheet are fired in a kiln. The epoxy burns off, leaving an embossed effect of pure fused glass on top of the glass backing sheet.
Carving the Frit
The dried frit powder is carved away by a computer-controlled machine. The machine carves the bump-map of the photo created earlier by the design software. Where the photo was dark, frit is not carved too deeply, where the photo is light, the frit is carved away. All of this carving is done in a small height region, the frit ranges from only .050” thick down to 0.00” thick (completely carved away).
Pouring the Frit Slurry
To prepare the glass, powdered glass frit is mixed with epoxy, poured onto a substrate sheet of art glass, spread evenly, and then allowed to thoroughly dry.
InFusion Art Glass has developed a custom suite of computer programs that convert the photo into a set of commands to drive a computer controlled carving machine. The program turns a grey scale photo into a height map. That is to say, where the photo is dark or black, the program creates a high point. Where the photo is light or white, the program creates a low point or near zero-height point. This conversion of blacks and whites into differing heights is called a “bump map”. It is a 3D representation of a 2D photo. It is then converted into machine code that controls a computer driven carving machine.
The Inspiration - Any Photograph
I can start with almost any photo in electronic format (jpeg, gif, etc.), or a hard copy that can be scanned into electronic format. Some photos are better than others, depending upon the level of detail and the size of the features. Close-ups of faces, both human and animal are usually very good subjects.
Carved frit is a unique glass fabrication method that produces an embossed photographic appearance, while maintaining a “painterly”, almost pointillist-like effect. Developed by InFusion Art Glass, this technique combines modern computer controlled carving machines with centuries old stained glass techniques.