I have been using the same fusing shedule for several years now and just recently I started getting big bubbles in my projects Anyone with any ideas why or what causes the bubbles?
Lots of thing can create bubbles. More info required. What size? between layers? uder whole?
More information on layup and firing schedule would help.
If you fire the tiles upside down, the bubbles will migrate to the original bottom. Then a quick fire polish can avoid much of the mumps appearance. Needs to be really well cleaned both times.