ARTWEAR DESIGNS IN GLASS BY Ingrid Hein
Tutorial EDP better called SDP Sweet Dreamy Purple!
Feb 2008 addendum: I discovered this week that when working edp and
checking for color development, you need to take off your flameworking
glasses to SEE. These glasses tend to make things look PINKER. It
made a difference for me and I knew when I had to continue to color up
the beads.
Moretti Glass- "Special" "Expensive" "Hand Pulled" Whatever they
are called, I am posing a theory on glass colors that have been
called difficult or evil. The basis of my theory is this glass will
separate based on temperature gradients such as are found in these ends
of Moretti Purple. Picture below of the ends of hand pulled
canes. The
rods in question are those that have concentric rings of color inside
the rod and can be viewed by looking at the end. I am using
Moretti purple since this was the glass that led me to my suppositions.
This is not the greatest picture but it is good enough to demonstrate
the internal concentric bands of color variation from batch to batch.
When a glass gather is pulled, the gather will cool from the outside
in. This means that there will be different temperatures in various
layers as they cool . The variation appears to cause the glass
components to separate, hence the concentric bands.
A perfect example is Moretti Purple sometimes or all too
often called Evil Devitrifying Purple.
My history with this glass was initially brief. I melted it and
reheated and it devitrified.
I put it on the shelf and didn’t touch it for 6 months.
In the picture to the left you will also notice that not all rods of
this color are equal. Personally I would prefer the rods that have the
X by them for more than one reason. First the colors are more intense
and secondly the the cooling seems to have produced a thicker layer of
the color that I want.
HOW
DID I
COME TO MY CONCLUSIONS? When you melt a rod of purple and
lay the rod down the tip of the rod looks different than the rest of
the rod. The tip is more transparent and the color is more intense.
This mean t to me that with heating the rod these various components
are homogenized and on cooling they quickly separate out just as the do
when the initial batch is pulled. The color bands inside the rod are
examples of the glass components separating at different temperatures.
After heating the rod and forming a gather I lay the rod down. The
color at the tip of the rod of Moretti purple was the color I wanted.
Why did it separate?
Because the glass behind the tip is cooler than the glass
at the tip.
The tip enters a rapid cool.
When you are making a bead the interior is hotter than the
exterior.
So when reheating the bead it will often give you either
evil devitrification or a pale color(like the color of the
outside of the rod) rather than the color of the tips of these
rods.
If you don't want the color of the tips you probably don't have to do
anything different. The base color of the rod is easy to obtain.
My method of dealing with this glass is to let the bead cool down (for
a small donut of say 15mm I would say 20-30 seconds) and
then just introduce it to the flame to get a surface glow all around
the perimeter.
This takes less than 2 seconds.
I bring the bead up under the flame and wait (1 second maybe 2) to see
the glow and then rotate the bead toward me. (There is a reason why I
rotate toward me but I am not sure it is relevant.) In essence I wanted
the bead to cool the way the tip of the rod did. I needed the core
cooler than the exterior. Then just bring the exterior to a glow. So
how long do you let the bead cool? I have never timed it but you can
work this out for yourself. If the bead shows devitrication at the
edges of the flame, the interior was too hot.
If it breaks, it was too cool. * Generally I might have a small amount
of devitrification in the pucker. This generally is does not detract
from the wearability of the bead.
AS A SURFACE TREATMENT:
Moretti purple colors up the most when used as a surface treatment on
an opaque base. This makes perfect sense since there is so little of it
on the surface that rapid cooling is a given.
One other property of this glass has to do with its willingness to
separate. Corina Tettinger published in her book a look called
“kaleidoscope.” This
takes advantage of another property of this color- the willingness to
separate. When applied to the surface of a bead and melted beyond flat,
the glass continues to migrate. The opaque component is left
behind and the transparent continues to flood outward. The transparent
component spreads out faster than the opaque and you will get lines
that form at the spreading edge of the glass with a concentration of
color in the center.
Corina's Kaleidoscopes.
These beads take advantage of moretti purple to separate. Ok this isn't
the greatest bead or photo but you get the idea. The x's show where the
purple separated and the more transparent component migrated out over
the coral. The x's here show the lines formed over the coral from the
dots of purple. For this effect you really do need to let your bead
cool and reheat or you will get devitrification. Just looking at the
dots of purple you can see the opaque color isn't as intense and the
edges are not clear...because the transparent component to the edp has
migrated that far out over the coral. OK this is a work in progress. I
would appreciate comment, corrections, questions. You may email me:
HOW
DID I
COME TO MY CONCLUSIONS?
The
rods in question are those that have concentric rings of color inside
the rod and can be viewed by looking at the end. I am using
Moretti purple since this was the glass that led me to my suppositions.
This is not the greatest picture but it is good enough to demonstrate
the internal concentric bands of color variation from batch to batch.
When a glass gather is pulled, the gather will cool from the outside
in. This means that there will be different temperatures in various
layers as they cool . The variation appears to cause the glass
components to separate, hence the concentric bands.
This
takes advantage of another property of this color- the willingness to
separate. When applied to the surface of a bead and melted beyond flat,
the glass continues to migrate. The opaque component is left
behind and the transparent continues to flood outward. The transparent
component spreads out faster than the opaque and you will get lines
that form at the spreading edge of the glass with a concentration of
color in the center.