Several years ago, the geniuses at Uroboros developed two ‘red reactive’ glasses- one opal and one transparent. Kat at Uroboros explained the glass to Figimodo (when he visited the factory- see pics on our FB Page) as a ‘copper bearing glass without the copper’, so when copper is introduced to this glass you will get an interesting reaction. Copper bearing glasses are blues and greens and when these colours meet one of the reactive bases, the junction between the two pieces will turn red. The strength of the reaction varies depending on the amount of copper, and the temperature and duration of the firing process.
So, to better illustrate this Mikey and Zenia picked some SP 233.74 Turquoise Blue Opal, some red reactive opal, black (for a base) and three different Slumpys molds (SM 9125, SM 9050, SM 298) and made some samples to show this cool effect.
Zenia wanted to make sure we could show you the reaction when you use the reactive opal as a base as well as an accessory, so she had Mikey cut the plate bases (with black for the bottom layer to add volume to the piece) while she crushed some frit- both the turquoise and the reactive opal.
The pieces were placed in the kiln and both medium and small sized frit was sprinkled on top to give a fairly full coverage.
They were then taken to a full fuse (around 1460F, Mikey's not so good at accurate note taking I've discovered... Zenia) to smooth out the surface and encourage a good colour reaction.
Once fused, we then slumped them to get the final product!