I've seen instructions to use bannetons/brotforms, and seen people use them - but I don't know the reasoning for them. I understand that they're for letting dough rise, but I've never seen an explanation of why you'd pick willow or linen-lined or whatever material. They usually talk about airflow, but I though the ridges or linen were more designed to hold the flour on the sloped sides of the bowl.
Can someone with experience shed light on this for me?
(my next step is to buy some)