Posted By: cUpcAkecOok 
Jul 28  # 11 of 12
i didnt think that my pan was aluminium. I have the half sheet jelly roll pans, but i dont think that they are industry size, because i do have to cut my parchment papers to fit. I bought my pan at this GREAT cooking supply shop where i live. I think it might be the only one of it's kind in southern california and they've been around FOREVER! it's called Cookin' Stuff and it's one of the those great local shops that just about everyone and their grandmother (probably especially their grandmother's) know about. They only sell everything that has to do with cooking from knives to mixers and cute accessories such as magnets and aprons! My mom and sister and I have been going there forever so i guess i'll have to go back and get better ones.
 Posted By: KYHeirloomer 
Jul 28  # 12 of 12
Triple C, try putting a kitchen magnet on the pan. If it's steel the magnet will stick.

But, if they're not standard sizes, I suspect they are aluminum and designed for the home market. The steel sheet- and half-sheet aren't all that expensive, actually. And they won't do that dance in the oven.