QIC tapes are something different from DC300 and DC100
tapes. 
 Really?  DC300 = quarter-inch tape, 300 feet, written by lots of
 "QIC" 4 and 9 track drives in serpentine fashion, including the IBM
 6157.  My old 3M catalog lists it as a quarter-inch tape.  I've got
 one here; fits in a standard-sized QIC drive and works like any other
 QIC cart (e.g. DC600A).