boardbutproductive

Thanks all-- I'm not sure if it's coffee or mold, but either way, I'm planning to refire it to see if that helps. I figure either it fixes it, or this mug goes in the bin like it would have anyway. Amaco suggested decreasing the HF-9 glaze I used inside from 3 coats to 2, as they said it looks like the glaze pooled here, causing lots of little bubbles that eventually wore through. I plan to try that going forward, and also to run some tests with the orange underglaze. Everywhere I used that orange, it turned into a sort of orange-peel texture (no pun intended) after glaze firing.

Hi all! Question- About a year ago, I made a mug using velvet underglaze and zinc-free clear. In the past few weeks, I have noticed that the bottom interior of the mug has developed pinholes with little black dots, and the clear glaze has started to look a bit milky. (See attached pic) The clay body is laguna cone-5 Bmix, fired to cone 5, so it should be vitrified. Any ideas what is going on here? Is it still food safe?