Y'all might already know this but if you have a local restaurant supply you can get heavy duty cookie sheets for much less than the thinner one's they sell in the local stores. We get ours there and they are very heavy duty and last forever. A side tip, I've bought a few for the garage for when I have to degrease something. They keep my workbench top clean. You can also get the nitril type gloves there cheaper than Harbor Freight.