I like the fact that not only do these bags vacuum seal like the ones you make, but you can open them, remove the amount you need, then reseal. My favorite use for the gallon sizeis for loaves of sliced bread because we don't usually eat it all up before it goes stale, and just putting them in regular zippered bags they get freezer burn and taste off. I put the load in the freezer when I first bring it home, when it's fresh.The next day I transfer the slices to the zippered FoodSaver bag and vacuum seal through the specially designed port. When I want some, I just take what I need and reseal. Zap for 10 sec on the microwave at 50% power, and it's like the slice is right out of the oven. When the bread is gone, I just dump any crumbs, and reuse the bag for another loaf!