Abstract: A tape cartridge comprising two halves each comprised of a rectangular panel with a peripheral flange along three sides and portion of a fourth side to permit the panel adjacent the fourth side where the flange is not present to flex. Access openings in the flange at one of said three sides which lies adjacent the fourth side and said fourth side to provide access to the interior of the cartridge. A curved wall on the inner face of each panel, the walls having openings therein to align with the openings in the flange. Locating means to locate the cartridge halves one relative to the other in an assembling operation and releasable catch means to secure the halves together. The catch means being located at the fourth panel side and the panel side opposite the fourth side and the side which lies adjacent the fourth side but does not have the access opening.