There's a great way to help you easily avoid soggy picnic sandwiches and similar lunchtime woes, and it involves a simple storage tip: wrapping your sandwich in parchment paper.
Parchment paper is porous, so it will allow your bread to breathe while keeping excess moisture away.
Be sure to double-wrap your sandwich — wrapping it once, cutting it in half, and wrapping it again — for added protection.
If you have time, wrapping all the moist ingredients separately and assembling them when you are ready to eat is an even better way of ensuring your bread doesn't turn to mush.
Because moisture from condiments and other wet ingredients can seep into bread and cause it to go soggy, packing them in separate storage containers can make all the difference.