Cardboard packing box for cartridge container

A cardboard packing box for storage of a cartridge container which has a case shell comprising two mating case shell halves identical in dimensions with each other and forming a plurality of compartments for receiving sets of a specified number of flat tape cartridge units therein, respectively, each said mating case shell half having at least one pair of bottom fitting flames different in size so that one of said bottom fitting flames of one of said two mating case shell halves is fitted in another of said two mating case shell halves by insertion so as thereby to be able to be coupled to another said cartridge container together, said cardboard packing box comprising:

• a cardboard box having internal dimensions substantially identical with a horizontal projection o said case shell of said cartridge container;
• and
• a pair of cardboard backing pads each of which is substantially identical in external dimension with said cardboard box and has a pair of openings which said bottom fitting frames of each said two mating case shell halves are fitted respectively by insertion.