Get the stainless steel lunchbox.

Stainless steel is the most durable and easiest-to-clean lunchbox material out there.

It’s basically the answer to both halves of your question at once. Steel won’t absorb smells, won’t stain from tomato sauce or curry, and you can toss most models in the dishwasher without thinking. Plastic eventually gets greasy and stained, glass is heavy and shatters, and those fancy bamboo ones look nice but soak up everything.

The only real downside is dents. Drop a steel box hard enough and you’ll get a ding, but it still works fine — it won’t crack like a hard plastic shell. For everyday lunch duty, that’s a fair tradeoff.

Just avoid the cheap ones with fragile plastic latches. Spend a little extra for a model where the lid is also steel or a solid hinged design. That’s where the durability usually fails.