I have used this type of bag for several years, traveling nearly every week. This is the first time that I have purchased this brand and it will be the last. The first time I used one of the large bags, I sealed up some clothes for 3-4 days as a test. The bags did not leak - great news. When I opened the bag, it ripped away from the zipper. Thinking I had been too rough with it, I tried again with a second bag. Same result. The bags that I have been purchasing from Target have been holding up for 15-20 trips before losing their seal. I was hoping for at least that much durability from the Space Bag brand, but I'll have to be disappointed.The plastic feels too thin to hold up to frequent opening/closing cycles. Maybe if you are going to seal it up then put it on a shelf, these may be for you. Otherwise, save your money.