The "LaserWriter II Owner's Guide" specifies the paper at:
16-lb. to 20-lb. photocopy or typewriter bond (60 to 80 g/m2) in normal
mode; up to 36-lb. (135 g/m2) stock in manual mode with face-up tray open.
We don't know of a way to use a LaserWriter to print on 65-pound paper. The
LaserWriter paper path will not support paper of that thickness, nor is there
enough heat to fuse the toner through paper that thick.
You can, of course, use the LaserWriter to print labels and stick them to any
thickness of paper. Labels as large as 8.5 X 11 are available.