Unglazed quarry tiles (terracotta clay) are cheaper than travertine, I would think, and they work great for me. Less than $1 at Lowe's or Home Depot, takes only 6 to line my bottom oven rack. Do not place any tiles on the bottom surface of your oven. Wipe new tiles off to remove any dust, then gradually heat them up a few times to sort of temper them.

I baked pizza this past weekend on my tiles. Heated them in a 500F oven for about 30-45 minutes, then slid the pizza onto the tiles with a wooden pizza peel. Pizza baked in about 8 minutes.

Leave an inch or more of space around the outside area of the tiles for good air ciculation in the oven. I leave the tiles in the oven pretty much all the time.

I purchased travertine tiles because I couldn't find the unglazed quarry tiles. I bought six 6inch square tiles for $2 each. They fit nicely on the oven rack and I get fabulous pizza on them!

I saw an episode of Good Eats and Alton Brown said to get a large drip tray that goes under the very large terra cotta pots.

The more I think about this the less I think I'm going to do it. You just don't know what all else when into making that terracotta or travertine for that matter. right?

Mary, I would not do it either.

I don't have enough background in Chemistry to assure me that it is safe to use items designed for none-food related purpose in my food preparation. Also, it is really not that costly even paying for a good pizza stone, especially if you will use it often for a long period of time.

Is it a good or bad idea to leave the baking tiles on the bottom of the oven when baking cakes in the middle of the oven? I wonder if this helps with even heat for cake baking, or would it dry out the cake too much?

Is it a good or bad idea to leave the baking tiles on the bottom of the oven when baking cakes in the middle of the oven? I wonder if this helps with even heat for cake baking, or would it dry out the cake too much?