Don't machine-wash a fabric lunch box

For a lunch box with fabric outside and plastic inside, the right way is to wipe the plastic liner and spot-clean the fabric — not toss it in the washing machine.

Machine washing is tempting because it’s easy, but that waterproof plastic lining is usually bonded or heat-sealed to the fabric. The agitation can break the seal, make the plastic peel, or wreck the waterproofing. I’ve seen lunch boxes come out of the wash looking like a deflated balloon with a crinkly inner bag.

So do it by hand. First, shake out the crumbs. Wipe the plastic lining with warm water and a drop of dish soap, using a sponge or cloth. For stuck-on stains, let a baking soda paste sit for a few minutes, then scrub gently. For the fabric exterior, dampen a soft cloth with a little mild detergent and spot-clean just the dirty areas. Don’t soak the whole thing — the padding underneath can hold water and get gross.

Then let it dry completely, open and upside down, before storing. Trapped moisture is how lunch boxes start smelling like a gym bag. If you do this after every few uses, you won’t need deep-cleaning often.

Treat it more like a backpack and less like Tupperware, and the lining will stay intact.