We made sugar cookies, chocolate chip cookies, Sherry Yard's oatmeal raisin cookies (recipe on E6), and Pillsbury "Golden Layers" refrigerated biscuits on each sheet in the writer's professional-grade Thermador gas oven. Performance in your oven may vary. Five stars is the top rating.
Calphalon Classic Nonstick Insulated Cookie Sheet$20, available at Bloomingdale's, 225 Boylston St., Chestnut Hill, 617-630-6000, bloomingdales.com.
Rating: 
If C is for cookie, C-minus is for this Calphalon sheet, which turned in pale cookie after pale cookie - and took forever doing it. During the sugar-cookie round, we removed the batch from the oven after 19 minutes, a full 5 minutes longer than other sheets. (Even then, the interiors were a shade underdone and the cookies never spread to their full diameter.) The light gray surface coupled with the insulating layer of hot air simply slowed down baking too drastically. The basically flat sheet (no raised sides) made removal with a mitted hand a daunting endeavor.

