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About Teresa Kowalski
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The medium used
in Teresa Kowalski’s artwork is referred to by several names,
such as fused glass, kiln formed glass, art glass fusion and warm glass.
The reason the term "warm glass" has been widely adopted is
because most furnace work, including casting and blowing, takes place
between 1700 and 2300 degrees. Compared to that, kiln work has taken
the secondary place of being only "warm", because operations
generally included in this category, such as sagging or fusing take
place anywhere between 1200 and 1700 degrees Fahrenheit.
During the process
of fusing glass, pieces of compatible glass are fired in a kiln to a
temperature between 1400 and 1500 degrees F until they are red-hot and
melt together.The glass is then fired a second time to a slightly lower
temperature to slump into the desired shape and then annealed (a slow
cooling process). Many unexpected and wonderful things can happen in
each firing that make each piece unique.
What is dichroic
The spectacularly vibrant
colors exhibited by dichroic glass are created by a very sophisticated
combination of extremely thin, clear, crystalline layers that interact
with each other and produce very specific reflected and transmitted
colors. There are no absorptive pigments used in this process. This
allows all of the light energy to be either reflected or transmitted
and, in turn, creates the rich colors that characterize art works created
with this glass.
Dichroic glass is created
via the application of many individual thin films on the order of one
micron in total thickness. These films are comprised of alternating
high and low index of refraction materials that produce multiple internal
reflections. Some of these reflections will add together constructively
producing very vibrant reflected colors. Others will add together constructively
only in the transmitted direction producing very rich transmitted colors.
By varying the thickness of the layers carefully, different colors can
be created, all with incredible vibrancy. The fact that the glass exhibits
both a transmitted color and a different reflected color is why it is
called "dichroic". Di- is Greek for two, and -chroic is Greek
for color, thus combined we have "dichroic", or two color.