Northstar Heat Sensitive Colors

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The opaque colors-NS-10 White, NS-11 Jade, NS-16 Black, NS-27 Green Exotic, NS-28 Blue Exotic and NS-29 Red Exotic,
and NS-40 Sky Blue, and NS-56 Pumpkin are heat sensitive. This means the glass must be treated with more care when
heating to avoid boiling. Use either a cooler flame or put the rod in a cooler part of the flame (the edges, or as far away from
the torch head as possible). The lampworker must watch the rod and if the glass begins to boil remove it from the flame
immediately. Otherwise, the rod can be "bounced" in and out of the flame to prevent overheating. Also, some lampworkers
report success by inserting the color into a clear tube, then collapsing the tube around the color. The color is then said to
be "clad" with the clear glass. This insulates the glass from boiling so easily.