We’ve had mixed success with
We’ve had mixed success with PearlEx (available from Michaels, Hobby Lobby, etc.). Many of the colors burn out very close to the temperature at which the glass melts sufficiently to stick to the mica. Some colors, for example, work great on black (thanks to its relatively lower melting temperature) but not on stiffer glasses. The key to micas is to test.
Helios Kiln Glass Studio