Choosing clay when everything in the catalogue sounds the same

Supplier catalogues describe clay the way wine lists describe wine. Here is the short version for somebody starting out.

Grog is the decision that matters most. More grog means more tolerance of your mistakes — less cracking, less warping, more forgiveness on a join. It also means a rougher surface. If you are hand-building and new, take the grogged body.

Firing range has to match your kiln, not your ambition. A stoneware body you cannot fire high enough is an expensive way to make something porous.

Colour after firing is not colour in the bag. Ask to see a fired test tile. Any supplier worth using has them.