Ziploc bags? Those are so last Tuesday, and a pretty dang expensive way to store something. I mean, really, you put some nuts in one, take it to work, then throw the bag away... That's not just a waste of resources, it's a waste of money.
That's why we're fan of Crafting Tree, a local Spokane Etsy outfit that, among other things, creates reusable zipper baggies. They're the perfect size for a sandwich or most anything else lunch-food related.
Sturdily built, nice looking, lined with food safe nylon fabric... Clean with water or put them in the washer.
And at $10 a pop they're a steal. We're fans, and so should you be.