Either, depending on your mandrel. Make them to fit the mandrel you have.

There are several good YouTube videos on making the sanding drums, with tape and with glue.

Double stick tape on a ½ in. Dremel sanding drum works pretty well for a few applications of tape, WD40 will remove the tape, clean with alcohol and apply new tape. Works well for High grit Wet and Dry or polishing film.