Most historians believe
that the first fusing and kiln casting was done by the
ancient Mesopotamians in the year 2000 B.C.
The Egyptians and Romans were the
most prolific and many examples of their work can be viewed today in
museums around the world.
From 1500 B.C. to
around 500 A.D. glass fusing was very popular. After 500 A.D. until the
early 1900's glass blowing was the most popular glass art technique.
This is likely because of the demand for utilitarian glass used for
eating and drinking.
In the 1970's the
modern stained glass movement was well under way. Glassblowers in
Portland, Oregon and stained glass artists began to experiment with
creating art from glass fusing. The first company to develop and produce
"compatible art glass" was started in 1974 in Portland, Oregon.
If you recall your high school
chemistry,
coefficency of expansion, commonly referred to as
"coe" is the rate which glass expands and contracts. When glass expands and contracts at the same rate is said
to be compatible. If one or more pieces are joined together in the
process of fusing that do not have the same coe, it will pull away. It will
break.
If not immediately, eventually.
Artists arrange chunks of
glass, called “cullets,” and sheets of glass into a cold kiln and heats
them until the pieces stick (or “fuse”) together into a desired design.
Kiln-fusing techniques include bending and shaping glass using the heat
of a kiln. More advanced techniques include “combing,” which involves
using a tool to distort the shape of the glass while it is hot, and
kiln-casting, which involves filling a mold with cold glass chunks and
heating the mold in a kiln. Such methods differ from the more popular
“hot shop” technique of glassblowing, where the artist heats the glass
and then shapes it on a rotating rod.
Dichroic Glass
"Dichroic" is defined as the property of having more than one color,
especially when viewed from different angles. Dichroic glass was
originally invented in the 1950's for the space industry.
Dichroic glass is created in a high temperature chamber in a vacuum
furnace. I heard it described as recreating space on earth. Thin layers of
metallic oxides, such as titanium, silicon, and magnesium are deposited
upon the surface of the glass. The coating is transparent, rigid and
stable it withstands temperatures as high as 3000 degrees.
It is not
affected by solvents or most acids.
This "coated" glass only became available outside of the scientific
community in recent years.
Before dichroic color was developed, there was not a man-made material
that possessed true iridescence. Examples of this in nature are the fire
in an opal or the iridescent blue wings of the Morpho butterfly or the
green of a peacock's feathers. The resultant colors are truly
captivating. They glimmer and change when viewed from different angles. For example a
piece that appears green when front-lit might appear red when back-lit.
These two colors are always identifiable with each other. Blue will always
appear red when back lit. The front-lit color is referred to as the
reflected color and the back-lit color as the transmitted color. The
colors are very pure such as a laser's color and they glimmer and shine
like a bright mirror.
The angle which the dichroic glass is viewed is variable. When a green
reflected color is viewed straight-on it will change from green to blue to
purple if you tilt it slightly. The transmitted color will
change from red to orange to yellow. Heating to fusing temperatures
further intensifies the colors.
In
contrast to an ordinary piece of glass, the light hits the surface and
enters the glass, part of the color spectrum is absorbed, energy emitting
from the glass is the color spectrum that is unabsorbed.
Neither words, nor even a photograph can
do justice to the beauty of dichroic glass. The way the light plays
with the colors must be seen in person to be appreciated. |