I've been reading that unglazed quarry tiles are a good cheap substitute
for a pizza stone. I was going to try baking a pie using a technique
which says to put the tiles/stone right on the bottom of the oven and
bake the pie on top. However, I'm worried the tiles will scratch the
interior of my oven. This is probably a stupid question, but can I put
something less abrasive under them in the oven (and what would that be?)
or does that basically defeat the point as they have to be directly on
the surface of the oven? OR, will it work just fine if I put the tiles
on the lowest rack?