red porcelain coffee cup at 800x magnification

I assume you are seeing bubbles in all the glazes you have studied? Also saw the scale you used in another pic: can see where that would be handy. Perhaps you should start a glaze thread with these pics: many find the close ups interesting.

Hi Nerd, yes seeing bubbles is pretty much all glazes.  see a thread started by Joel called Bubble Bubble Toil and Trouble if you haven't already.  I make a lot of comments about my own bubble research and observations there.  Yes, scale is critical - bubbles below a certain size are there, but cannot be seen by human eye.  It seems clear industry depends critically on this fact.  I may trot out some of these pictures again at some point if the bubble discussion re-emerges.  I think it ended up in a chemistry discussion really.  The righteous path on bubbles as I see it now is about particle sizes and relative amounts of fluxes vs very refractory materials in the glaze.

Found it, read it.