Originally Posted by holotone
If it's Neutron, it's almost certainly medium. If it's Proton, it'll say 'soft' on the stamp.
That's true for all the newer proton but the older protons didn't have that...they were marked with an S on the outer ring in silver ink if they were soft. I was confused about that for a long time, I had a bunch of older proton ions that felt like softs but didn't have the soft stamp, now I know.