I buy my vac bags on Ebay. My research a couple of years ago showed that Weston bags had the lowest failure rate, so that's what I buy. I only use the rolls anymore when I'm vac-ing something like whole salmon. I get the different sizes that fit whatever I'm freezing. It's a time saver not having to cut and seal twice, especially when doing a seal run of 50+. You can find thicker mil rating on for SV also.