These are nice. I usually buy the freezer storage bags so they can be reused. And, yes, I would wash and use them several times before discarding. These have a firm top seal and the edges have double seals. I am not concerned about leaks. Regular storage bags went thru an evolution of just being flat to ones that have a pleated bottom. These are flat (hence my 4 star rating) and not pleated. If they would be pleated, 10 stars! Not there yet. These are quite nice and I am glad I got them. They will save me money. Smallest ones for snacks. About the same size as original snack size bags. The middle sized ones will fit a sandwich but as long as the sandwich does not have a lot in the middle. The large ones would work for the stuffed sandwich. The large one is smaller than a gallon size but should be plenty of room.