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Bubbles in larger pieces. I have been having large bubbles in my pieces lately. I have a 18” round flat clear piece (Spectrum 100 SFS) with text on the top and bottom with a long thin design in the middle. There are large open areas on either side of the design. After fusing I have been getting large bubbles (4 or 5 inches in diameter) in those open areas. I tried putting small clear shims around the outside of the disk hoping that the middle will settle first and let the air out, but this isn’t working. I made sever of these years ago and never had this problem, now I can’t get it to not have the bubbles. I have also had some bubbles on smaller pieces using the same clear base but not this bad.
Any ideas?

1) You didn't post your schedule, and that would help.
2) You can look in the archives for "bubble squeeze" and probably get all your questions answered.
-Or-
You can tell people you meant to make the piece that way.

In addition to your schedule, a photo would help.

It sounds like you've got a SINGLE LAYER of glass, with imagery on the front and back, and then a few design elements, like the long thin middle piece. If so, it sounds like a volume control issue. If there's a single layer of glass touching the shelf, and then areas of two layers, the single layer areas are more likely to bubble due to not being weighed down. You want to have two full layers of of glass for optimal results. I do my third layer accents with thin glass, to minimize spreading.