Has anyone experienced warping with Aventurine Blue or other shades? I was making an on-edge plate, each cut was 3/8" width by 12" long. As I was stacking the pieces, I noticed that several pieces were bulging out. I did not want to redo with a different sheet of aventurine, so I just tightly dammed the sides inside the kiln. The result was kind of interesting -- more of a wavy affect because of the warping---but not what I was aiming for. Note: I make on-edge plates alot, and often with Aventurine Blue. Never had a problem so I think the production of the glass is at fault here.