I know that paper isn't generally as good as toilet paper for tinder to use with a ferrocerium rod. However.... paper is packaged in a nice compact format, whereas toilet paper takes up a lot of space.

• different types of very thin paper are tracing paper, tissue paper, onion skin paper, rolling paper, and glassine paper
• there ARE some fairly compact forms of cotton:
  • cotton pads
  • cheap single-ply compact toilet paper
• you can also buy off-the-shelf cotton balls, and squeeze the fuck out of them