how tight and what kind of liquid are you putting in with them? and what temperature…dont cook them 
hah!
Better buy A5 bubble envelops and put them in those (1 per envelop), the inner lining of the bubblewrap is ‘smooth’ and less likey to leave marks. If you don’t want the paper look, you can also rip out the bubbles but that’s a big ugly 
And as geg says, chance you’ll warp/damage the packs in just normal climate is unlikely.