Abstract: A sale packing of the blister type comprises a backing plate having undercut side edge recesses for receiving and holding opposed edge flange portions of a domed front cover. The backing plate along at least one edge is additionally provided with protruding edge flange operable to be received in one of the underout edge recesses of a similar backing plate of another corresponding packing by insertion of the edge flange for edgewise joining the two backing plates as separate elements perpendicular to each other. The four similar backing plates are joinable into a square tube element. The backing plates further have at least at one side thereof a number of ribs or grooves extends parallel with the backing plate side edges in such a manner that these ribs or grooves of opposed inner walls of square tube element are operable to support the opposed edge flange portions of one or more of the front covers to enable these as separate elements to be mounted in a drawer-like manner in the square tube element.