Vacuum chamber machines are generally powerful enough to compress fruit and veggies in to a terrine-like stack. Its less the power of the vacuum and more the method of vacuum that makes the difference. FS machines can actually pull a very strong vacuum. I've been thinking about this, and I think I've figured out why it works with a chamber vacuum and not a bag sealer. When you have the fruit in the chamber and evacuate the air, you are creating a low pressure environment in the chamber. This should have the effect of "sucking out" the air in the little spaces throughout the watermelon. The the bag is sealed around the fruit, and when the chamber is opened there is an even 14.7 psi of pressure which closes all the empty spaces created when the air was sucked out of the fruit, thereby compressing the fruit. ← When I bought my Foodsaver, it came with three canisters, like these: Foodsaver canisters Do you suppose that the Foodsaver would generate enough vacuum to successfully compress fruit in these? While compressed fruit isn't high on my personal to-do list, I would be happy to provide some experimental results, if someone wants to guide me in the prep.