100% vacuum = 10 tons (not going to happen!) (on earth)
80% vacuum = 8 tons of pressure in the bag. Which equals 25 mmHg.
This is per square meter, I have to add.
Thats what I use and in my oppinion the material gets a good squeez! and I get a good bond between the layers.
I have to say that I only live 10 m. above sea level. Which gives a better atmospheric pressure.
