Keilim 15:2

Bakers’ wooden boards are susceptible to impurity but those of homeowners are insusceptible; if the homeowner dyed them red or yellow, they are susceptible. Rabbi Eliezer says that a baker’s shelf that is attached to the wall is insusceptible to impurity but the Sages rule it susceptible. A baker’s frame is susceptible to impurity but that of a homeowner is insusceptible. If the homeowner made it a rim on all four sides, it is susceptible to impurity; if one side was left open, it is insusceptible. Rabbi Shimon says that if he modified it so that one could cut dough on it, it is susceptible to impurity; a counter is likewise susceptible.

Keilim 15:3

The reservoir of a miller’s sifter is susceptible to impurity but that of a homeowner is insusceptible. Rabbi Yehuda adds that that of a hairdresser is susceptible to impurity as a seat because girls sit in it while their hair is being done.