A word of caution regarding kiln shelves
As a baker and a ceramist I thought I would put some information regarding the use of kiln shelves for baking bread. I don't know what the effect of using a NEW kiln shelf for baking would be but I do know that kiln shelves that have been used to fire ceramics are most often treated with kiln wash to prevent glazes from sticking to the shelves. The kiln wash is made of silica sand, alumina hydrate and kaolin and this is NOT a food safe material. Usually the underside of the kiln shelf is not treated with this so it may be possible to use the untreated side of a kiln shelf, but once fired the kiln wash is impossible to remove and caution should be taken so that it does not come in contact with food.