The mug on the left was bisque fired and then glazed, the one on the right was glazed in the green (dry) state. The glazes are the same inside and out but the porcelain one the right is based on New Zealand kaolin (vs. American kaolin on the left). Three secrets for success for the one on the right were: It was glazed inside and out in two operations with a drying phase between, it was heated to about 150F before each application and it was fired with a soaking period (at about 1900F) on the way up to top temperature (cone 6).
Once fire glazing
Refers to the practice of firing ceramics in one firing (rather than two) to produce a fully glazed product. This practice requires more technical expertise.
How to Liner-Glaze a Mug
A step-by-step process to put a liner glaze in a mug that meets in a perfect line with the outside glaze at the rim.
Glaze Pinholes, Pitting
Analyze the causes of ceramic glaze pinholing and pitting so your fix is dealing with the real issues, not a symptom.
Plainsman Electric Bisque Firing Schedule
Three-step to 1832F