Bubbling or Boiling Glass

This is my first take on the "bubble-up" effect in fused glass that is achieved using bubble powder.  The process is really simple - you stack three or more layers of glass, place bubble powder in between one or more layers and fire to 1700F.  What is not simple is figuring out the details - which glass to choose, how many layers, what order to stack it in, how much bubble powder to use and where to place it, etc.   

I combined 3 layers of glass and what I thought was a lot of bubble powder on top of the bottom layer. Well, I should have used more powder, placed it differently and the white glass I chose was wrong - there is clearly not enough contrast.


Attempt number 2 - I used more bubble powder, a darker green and opaque white glass.  The bubble pattern is much more pronounced and the white did not turn into murky clear.  However, there is still a lot of small surface bubbles and some of them have burst, so the surface is not smooth.  Also, the bubbled-up areas look fuzzy - I don't know if I like that...  I'd rather they look like bubbles and not like small explosions.


Attempt number 3 - sightly lower temperature.  The explosions are slightly less fuzzy, and there is more middle color showing.