It can be very frustrating to open up your kiln and see a glass bubble staring you in the face. So why do bubbles form in fused glass? The bubbles are trapped air between your glass layers. And the short and sweet reason why they form is because your glass layers seal before the air can escape.

Three ways you can help ensure that your warm glass work won't be ruined by bubbles:

1. If your going to use clear glass as your top layer make sure it's not a full-size piece. If you cut it into smaller pieces the air will be able to vent out. Don't worry about your top clear piece looking bad since it will combine back together after a full fuse firing.

2. At the edge between larger glass layers you can place a small 'lift glass' piece. The 'lift glass" piece will hold the edge up longer allowing the air to escape because the center will slump first.

3. Called a 'bubble squeeze' adding a 1/2 hour soak time around 1200°F (650°C) may help prevent bubbles from forming in your warm glass work. Also slow your ramp speed down between 1050°F to 1250° (565°C to 675°C). This will give the bubbles time to escape before the edges of your glass artwork seal.