I operate the 3302m. And I have run the 12 point card.
I have the operators manual. Not in front of me tonite. The measures are all metric in my manual, and when needed, I must calculate to imperial measures.
At college, 25 years ago, a point was 1/72 of an inch. So I surmise, 12 point stock is 12/72 of an inch. Now, a prescisioned caliper, which I don't have, would measure that thickness.
But like the previous dude remarked, you can get the specs off the internet, if you don't have a manual. At this point, I would say that 12 point card stock is 12/72 of an inch.
Calculate that into metric, and compare to the manual specs.