craters in fused glass

[artyglass]

I to use spectrum 96 and have come across this mainly in black glass.  There are a couple of things to prevent air getting trapped in larger panels the first one is to place small pieses of glass at intervals under the panel, so the glass is sitting up off the shelf.  The other is to cut only the top layer of glass in half then half again.  Both of these allow the gas to escape as the panels are large and the larger thay are the less chance the gas has to eacape. This works for me.  Good luck