The media should ideally enter the printer from directly behind the printer and pass through the fanfold media slot in the rear of the printer. (Use the instructions in Printing on Fanfold Media
to insert the externally-mounted media into the printer.)
The media should move smoothly and freely. It should not slip, skip, jerk, bind and then move, etc. when mounted on your media stand.
The movement of the media roll should not be impeded by contact with any printer or other surfaces.
The printer should be placed such that it may not slip or lift up away from its operating surface while printing.