Etched pattern on CBS Rainbow 2 on thin black, COE 90.

Note on Rainbow 2 coatings from CBS: In the highly scientific world of dichroic glass, the Rainbow 2 is the most difficult to produce. On occasion, slight peeling/flaking of the coating during the fusing, lampworking and/or glassblowing process can take place. This is usually isolated at the gold edge of the Rainbow 2 sheet only.In the Art community, this peeling/flaking of the Rainbow 2 is a generally known fact, and many fusers test fire a strip from the gold reflected edge of the sheet to ensure the coatings are stable and to predetermine color shifts.