Old Buckley Barm or Yeast pot. I found this one in a shop today, cheap as chips!
I've increased my firing temp by 30c and allowed the plates to soak for an hour and it's made a huge difference to the finished pots. They are inspired by a nice Dylan Bowen Platter I have on my wall. Pleasing results I might do a few refires and see if I can get a few slip trailed pots to get a little more movement going on with the higher temp and soak. Might be the beginning of something that floats my boat more than the results of the way I have been firing for the past few years. Of course it's not as pleasing to me as a wood fired pot but the result is getting closer.