Everyone is always talking about COE and how it is important that the glass you use together is compatible. But how are you to know if your glass is compatible? Test it.

There are four main ways to test glass compatibility. These include:

• Base glass test
• Freezer Test
• Polarized lens test
• Thread pull test

One way of testing warm glass compatibility is the Freezer test. In my opinion this test is one of the easiest to administer and is a general test for stress. It's simple. Step 1: Fuse your different glasses together. Step 2: Place in freezer. Step 3: If it doesn't crack after returning to room temperature than your good to go.

For more ways on testing glass compatibility please refer back to our How To Make... page.