Polarized film (filters) are used to detect internal stress in fused glass.  The stress can be caused by multiple things, including incompatibility and poor annealing.  If you aren't sure if two types of glass are compatible, run a quick test and you can see.  This photo is of different types of bottle glass frit fused onto window glass.  You can see by the light flares that there is significant incompatibility.  Click through to see the entire process.  Once you have a set of films, you will use them constantly, and feel more secure knowing  your artwork is perfectly annealed.

 

Keep those kilns hot!

 

Jodi McRaney Rusho

 

Watch for my next online glass featuring modular texture tiles for amazing DIY texture that is unique and reuseable.  There is no charge to watch the live broadcast, register now to make sure you don't miss it!