I have no idea. That’s why I asked all of the questions. Why don’t the flat tins do that?So what exactly is being released that causes the bulge? C02?
Ive noticed when I jar tobacco that the longer its been closed the more of a vacuum it seems to put on the lid. Why would there be negative pressure in the this case but positive pressure in a sealed tin?
I mean…. we know why GLP’s tins do that…. because of black magic, but why C&D?