Review on Bakeware Nonstick Technology Dishwasher Heavy Duty by Missy Dawson

I bought two of these nonstick pans just because I didn't want them to warp. I used both trays for the first time at 425 degrees a few days ago and no problem. Today I preheated the oven to 375 degrees to bake french fries and two pork tenderloins and after putting both baking sheets in the oven I heard a very, very loud knock. I opened the oven door and you can see in the picture that the top pan is very deformed. If I were to cook something that could move/slip, it would spill out from the bottom after the curvature occurred. In fairness, it should be noted that after the trays cooled, the bottom straightened and the tray flattened out again. Unfortunately, based on what I know about metals, something that has been deformed once will continue to deform in the future when exposed to temperature. The non-stick coating works as advertised, but it was the warping issue that made me give it such a low score. If it didn't warp I would give this product 5 stars.