Why not go with Anchor Hawking or Pyrex glass?

Glass is a bit heavier to carry and kids aren’t too careful with them so we’ve been looking at stainless steel alternatives.

Ah, that makes sense. Guess I didn’t think about it from a heavy perspective.

Rectangle will fit best in many common insulated carriers, like the Fjallraven.

The one with the best leakproof lids.

Love, your lunchboxes.

From a storage perspective I prefer containers with straight sides so there's no rolling. For stainless steel containers I only have experience with round and rectangle.

I don’t know how old your kids are, but mine lost lids so I found the planet box lunch boxes to be the best solution for us. Easy enough for even a preschooler to open, can’t lose the lid, completely stainless steel. Our oldest used his from first grade through seventh daily and it still looks brand new.

Second planet box. We use the same for our kids.

Rectangle or square for me. Sandwiches and many other foods are normally shaped like that, but round is good for a lot of Asian dishes too.

Is there an issue with acidic foods like pasta sauce?

Don’t forget glassware exists too. I buy the Rubbermaid brilliance line and it’s built much better than most of the plastic ones. It comes with a lid that doesn’t just fold the plastic and break off, it has a hinge.

The Ikea 365+ ones. The lids are the same through the whole line (and they sell them separately), they are watertight and they don't scratch. I think they have both squared and rectangular ones in steel.

Not really, otherwise how would you cook pasta sauce even? Good stainless steel is ok

The difference is cooking is typically way shorter time than food storage. Google it, but here's a snippet I found..

"Since proteins can form complexes with metal atoms, such as iron, in the pan, and acidic foods, such as tomatoes, cabbage, lemon, sauces, etc., can react with the stainless steel, causing leaching of the material into the food."

Dude none other than onyx.

Circles are killer, I replaced all my glasslock with these