Clothes you do not mind ruining
Clay washes out of most fabric. Most. Glaze and underglaze can be less forgiving, and a drip on a favorite shirt tends to stay a drip on a favorite shirt.
Comfortable beats cute. You will be sitting at a wheel or standing at a table for most of the session. Pick sleeves that stay out of your work: short ones, or long ones that push up and stay up.



