A cassette system for any type of recording medium in strip or tape form, such as films and magnetic tapes, consists essentially of a housing whose external dimensions match those of a conventional type of cassette, and a protective holder for the recording medium which is wound into at least one roll. The housing and the holder are separate or separable members and can be fitted together. Both are provided with means for inserting the holder into the housing in the correct position, and for introducing the recording medium into the transport apparatus. The housing is provided with opening and closing means. The holder can be designed to be separable from the roll of recording medium. Preferably, the housing is a precision-made article and the holder a low-cost article.