I've had a few people ask where I got the bannetons (proving bowls) that give nice spiral patterns to the bread.
They're from a website called Manufactum. They sell all kinds of strange things, and they seem to be beautifully well-made. For example brass compasses, wooden toys, and their gardening section arouses consumerist feelings in me that I don't normally experience. Have a look. If you can confine yourself to buying only proofing bowls, I'll be very impressed.