Reactives

UROBOROS has come up with two unique glass formulas for System 96 that are designed to create a “reaction”, when melted against certain other colours. 
That’s right folks- one is a clear transparent glass and the other is a white opal that both actually really want to be red, but can’t be so unless we add copper to it. 
And how do we do that the unwashed hoards ask?

We mate it with a glass that's high in copper.

Copper is present in many blue and blue-green glass colours, in various concentrations resulting in varied effects. That’s why Spectrum along with Uroboros has published this chart above. Regardless, most will garner some sort of reaction (like Mikey did by leaving his shoes on while visiting the mother-in-law… The Missus)

For simplicity, on this chart all System 96 partner colors have been graded for their potential to react into three categories: Strong, Medium, and Mild. You will find that the intensity of the reaction color will get stronger with longer, hotter, or repeat firings. This is because the copper ions have more time to mingle with their friendly reactive partners in the adjacent glass. 

While the chart is reasonably up-to-date it is impossible for such large, slow moving multinational corporate entities to react with the deftness, skill and swift precision of a Mikey and the folks at Fantasy In Glass. Hence, we are able to add to this list-

on a clear base-
223.74- Strong                         
226.72- None
O/A 634.52- Strong
New FR (see pic)- Strong

on an opal base-
223.74- Medium
226.72- Medium
O/A 634.52- Medium
New FR (see pic)- Strong