I'm sure there are great vacuum seal bags that work effortlessly first time, but then there are the type that may require a little persuasion to start working.<br /><br />The secret is in understanding how the cost-optimised one way valve works, and how it may require a bit of priming to get it started.<br /><br />It's also useful to squeeze as much air out of the bag as possible before zipping the seal up and pulling the vacuum as it saves a lot of time.<br /><br />It appears that there are some 3D printing files available for making support and airflow disks to use under the seal in these bags to make them work better.<br /><br />I ended up getting a rechargeable pump, and it still takes a while to suck all the air out.<br /><br />These bag and pump kits are very common on AliExpress (not a sponsor). Here's a typical listing.<br /><a href="https://www.aliexpress.com/item/1005008585669872.html" target="_blank" rel="nofollow">https://www.aliexpress.com/item/1005008585669872.html</a><br />...<br /><a href="https://www.youtube.com/watch?v=8llI-EhyHg0" target="_blank" rel="nofollow">https://www.youtube.com/watch?v=8llI-EhyHg0</a>