J.S.
My mom uses them and they work great. But she found that warming the zipper and the cap with the hair dryer makes them easier to seal. You may have to re-vaccum them after a few years if they don't get sealed well, or if they are standing on end instead of flat, but they do really save space. She did clothes, pillows, and spare bedding for each room. But you would be amazed by the amount of space that was saved from the boxes of yarn!