Hi Petra,

Thank you for the tutorial, however, I do have some questions, if you don’t mind answering them. 

1. Is it only the white luminescent glass that has to be fired down? 
I do have other colors  and don’t want to waste them. 

Most of the luminescent coating will fire off when you have it up. The darker colors tend to keep it a bit more than the lighter colors. 

2. I did an experiment with the white glass. One was luminescent face down with a layer of clear on top. The other was luminescent up capped with clear. Results of full fuse was that the capped one lost all luminescent coating. 

Yes, when you cap the luminescent glass, the coating will vanish. 

 3. If I full fuse face down, can I then slump face up or would I lose the luminescent effect? 

I have draped luminescent glass at 1200°F with success, meaning the luminescent coating did not fire off.  

 4. What is the highest slumping temperature for the luminescent glass? 

This question I can not answer with certainty. It depends on your kiln, the distance to your coils and of course the color of your glass. If your kiln is high enough I would try to set your mold with the glass under another kiln shelf, which you can raise with some kiln posts. Make sure there are a couple of inches between the glass and the kiln shelf. 

 5. Is it always face down firing for all luminescent/iridescent glass? 

Iridescent glass is usually a high fire coating for all the fusing glass. The luminescent coating is a low fire coating which is less expensive and also has a different look to it. Your best bet will be to use it in reversed fusing projects. 

 Again thank you for your help. It’s really appreciated. Nicole

I have to thank you Nicole. Those questions are very good and thank you for letting me use them in our blog. I’m sure your pieces will still be pretty and not a waste, even if the luminescent coating fires off. Wissmach glass is still less expensive even with the coating than most of the other glass types you can get.