America Test Kitchen (ATK) executive editor, Hanna Crowley, gave some advice regarding your old sheet pan. She said that even if it’s old and well-worn, you absolutely should not get rid of it (just yet).

Hannah and all the other ATK chefs and editors know wherewith they speak. I’ve seen the ATK pros wielding sheet pans every Saturday morning for several years (thank you PBS!). They love ‘em and have tested them over and over for all sorts of purposes.

Technically sheet pans are rimmed baking sheets and they have oodles of uses: baking cookies, cakes, chicken, and fish; for toasting nuts; for roasting vegetables; for sorting dried beans; for cooling cooked pasta and rice for salads; their uses go on and on.

Add a wire cooling rack and you have the perfect vessel for roasting and broiling meats, holding breaded foods before and after frying, and drizzling chocolate over desserts or maple frosting over cinnamon rolls. In a pinch, turn a sheet pan upside down and you have a pizza stone or a pizza peel.

Their only downside is the few ways they can get messed up. For instance, have you ever heard that boinging noise after placing it in the hot oven? That’s the pan warping (the metal expanding in a hot environment).

All pans can warp, but a sturdier pan will warp less. The only way to avoid this is to buy the right pan. (After grueling trials, the pros at ATK found the “right pan” is from Nordic Ware, which beat out the seven other pans in their testing lineup.)

Another way pans get messed up? They change in color. Sometimes they just get dull—they’re still lightly colored but aren’t as shiny as they were. This happens as the surface gets roughed up.

Other times they darken or even turn black. This happens if you frequently roast things in oil. The oil polymerizes on the surface, like the seasoning of a cast-iron pan, and creates a layer that naturally darkens.

So does this color change matter? Is this a bad thing? To find out, Hannah and crew made an assortment of different foods in shiny new pans, then in dull and darkened pans. Surprisingly, they found that the dull and darkened pans actually browned better than the shiny new ones.

The science around this? Darker colors absorb heat more efficiently than lighter colors. Think about how if you dress all in black on a 90-degree day, you’re going to be hotter than you would be if you were in a lighter color.

But to be sure they weren’t imagining things, they put shiny new sheet pans and dull older ones in the oven with temperature trackers attached to record the rates at which they heated. Sure enough, they found the older sheets heated faster, hitting just over 400 degrees in 15 minutes. The shiny new sheets only reached 350 degrees in the same amount of time.

But now to the point of Hannah’s article. Your pan’s a little warped, and/or it’s discolored. Do you need a new one? She says “Yes, if it’s constantly warping. Chronic warping isn’t good and you might just need to buy a new, sturdier pan. But if your pan’s getting dull or dark, it’s actually a good thing because you’ll be able to get even more delicious browning.”

Her bottom line: Don’t discard that old pan too soon. If the warping is manageable, hang onto it. And if it’s discolored, just be sure to check your food a little earlier than your recipe says to avoid overcooking. (Thank you Hannah. You just saved me from spending some money, and loads of time. I won’t be trying to shine up that darkened pan anymore!)