Just transferred about 20-25 pounds from jars to Mylar. Used about 110 quart bags
Weight is less than half of what it was as glass weighs more than tobacco in any jar under a quart.
Used a hair straightener to seal.
Good info from @Sir Saartan and @blackmouth210. I've not been sure how much air to keep in my bags. I am also not vacuum sealing. In the beginning I was not pushing as much air out as possible, but then I took the tin approach to heart and have been trying to evacuate as much air as I can with my hands. I'll be able to tell the difference in a few years, God willing.