Zip-Zag holds patents and proprietary technology enabling them to manufacture a high quality resealable bag with an oxygen transfer rate comparable with heat sealing to keep ALL odors in! That means that almost NOTHING goes out or comes into the bags! No smells, no air, no liquids. Everything stays safely sealed inside: these bags are really airtight and waterproof. Do you need to store spices? Do you need to keep the aromas of your campfire meal sealed away from bears and other wildlife? Zip Zag bags are the best out there for any purpose you need. That’s why their resealable, smell-proof bags are vapor control: they seal in ALL the flavors and ALL the aromas. They are heat resistant and made with food-grade material. For real Peace of Mind. You can wash and reuse them, without losing any of the great benefits these bags offer. Zip-Zag brand bags are exclusively made in house allowing for an unparalleled quality control system. One of every three cases are hand tested for leaks and defects. That’s how they can make sure of each of their bags respects the highest standards of quality.