the thicker the paper, the smaller the stitches need to be so it'll tear off easily.
i've been tearing apart the fanfold paper with carbons in between designed for dot matrix printers. the individual sheets are 15 lb paper. (normal copy paper is 20 lb) i bought a HUGE box years and years ago to use for a lot of different things. i'm almost out, though, so i'm going in search of tracing paper light enough to tear easily but heavy enough to survive a printer.
next stop ... WallyWorld