i.A high-soda glaze that shrinks more than the body as it cools, so it crackles all over. We rub ink into the cracks after firing.
ii.Crackle is decoration here. On a mug it is a place for tea to live: use it on things you will not drink from.
iii.Plenty of soda, little lime. Soda shrinks a lot as it cools, and that sets the crackle.
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