Even before humans learned how to make glass, they were employing naturally formed glass (obsidian rock and fulgurites, which occur when lightening strikes sand) into knife blades, arrowheads, and jewelry. Manufactured glass is believed to have been invented in Mesopotamia and Egypt around 3000 BCE, and the eastern Mediterranean area was the world center of glassmaking for the next millennium. Warm glass, which is made by fusing different colors of glass in a kiln, was used in ancient Greek and Roman mosaics; and jewelry made of it was valued as highly as gold. Early objects such as colored beads and small jars were rather primitive and poorly made, but eventually the blowpipe (invented about the time of Christ) made glassblowing possible, which greatly improved the quality and made its production fast, easy, and cheap.
Glassmaking followed the spread of the Roman empire. The priceless Portland vase was made early in the Christian Era by layering of different colors and then cutting designs in relief. The rise of blown glass eclipsed the manufacture of kiln-fired warm glass for the next two millennia. The technique of glassblowing reached its highest perfection in Venice, where artisans created vases, goblets, bowls and cups which could be blown to any shape; and which was then decorated with lacework in intricate patterns.
At the end of the nineteenth century warm glass was revived as a decorative medium, and it has become a very popular technique in contemporary art and design. Inexpensive modern kilns make it an ideal medium for school art projects as well as individual artists. Typically it is made by placing pieces of glass of different shapes and colors in abstract or realistic patterns over a sheet substrate. Pieces are cut by scoring with a cutter, and then snapping off with a pliers. Small colored pieces can be held in place with glue. A clear sheet may be placed over the finished design. Then the piece is placed in the kiln. Amaco offers two different models of glass kilns: a small, tabletop model measuring 10" wide by 9" deep by 9" high, suitable for small projects; and a production model measuring 41 1/2" wide by 24 1/2" deep by 13 1/2" high for professional use. Both models fire to Cone 07, and are completely programmable, hence very easy to use. The design may be placed over a ceramic mold which will shape it to a predetermined form (other than flat) when fired.
Contemporary artists use warm glass kilns to create unique translucent tiles for mosaics and window designs. Warm glass shaped with ceramic molds in the glass kiln is used to create striking vessels, jewelry, decorative containers, and free-standing sculptures. Look to Amaco for top-of-the-line kilns as well as a wide variety of warm glass materials and tools.