A professional lunch box just looks like a bag.

The most professional lunch box is the one that doesn’t look like a lunch box at all — it looks like a leather tote or a business bag.

The problem with most “lunch boxes” is they scream lunch: plastic, bright colors, logos, cartoonish shapes. At a desk job you want the opposite. Stealth. Something that doesn’t make your coworkers wonder if you packed your food in a children’s toy.

Steel is your friend. A simple stainless steel container (Monbento is the classic, but any plain steel bento works) reads as deliberate and grown-up. It doesn’t absorb smells, it cleans in seconds, and it slides into a bag without drama. Pair it with a plain insulated tote — leather if you want to look put-together, dark canvas if you’re practical — and you’re done.

Avoid anything with a snowflake pattern, a handle that belongs on a kid’s backpack, or a logo visible from across the office. And skip the plastic clamshell. The quiet container that doesn’t leak and doesn’t announce your lunch in the microwave is half the professional look.

Nobody’s auditing your lunch, but a bag that looks like you’re headed to a board meeting will never hurt.