How we choose a glaze

Every glaze starts as a tile. We fire between forty and sixty of them for each colour, in batches of six, changing one variable at a time - the silica, the firing curve, the thickness of the coat.

The tiles then get used. They sit under a coffee cup for a fortnight, go through the dishwasher thirty times, and get scratched with a fork on purpose. Most of them fail. Chalk took eleven rounds before it stopped crazing at the rim.

The one that photographs best almost never wins, because a glossy glaze reads beautifully on a screen and shows every mark in a real kitchen. Matte is harder to make and harder to shoot, and it is the one you will still like in a year.