Abstract: The utilitarian object has a first part of a flexible material and a second part, adjoining the first, notably having at least one utilitarian accessory. The first part is an envelopment zone delimited by a casing in which is disposed a tie and capable of sliding on the tie between: a) a position of use in which the envelopment zone is appreciably flat, and b) a storage position in which the casing is gathered and the envelopment zone forms an envelope in which the second part is collapsed. The object is maintained in the storage position by locking the casing at the tie. It can be a backpack, the utilitarian accessory being at least one shoulder strap assembly and possibly a belt assembly. It can be a shopping bag, the second part having, as utilitarian accessories, two carrying handles.