thickness adjacent the cut edges for the respective windows of the liner to prevent fraying of the fibrous material application_number US 67119684 A description in the magnetic recording disc jacket assembly of the present invention the magnetic recording disc is of a conventional type namely it is formed by a base film covered on one or both sides thereof with coated magnetic recording layers and has a central hole for engagement with a drive shaft of a recording reproducing apparatus and an index hole formed in a predetermined position for detecting a tracking starting point the jacket is preferably made of a flexible sheet material so as to present a so called floppy disc jacket however the jacket may be made of a pair of rigid plastic plate materials so as to present a so called floppy disc cartridge the magnetic recording disc jacket assembly of the present invention is prepared by laminating a cleaning liner 2 of e g non woven fabric on the inner surface of the jacket sheet material 1 of e g a hard polyvinyl chloride sheet to form an opened blank 3 folding the blank 3 along the center 31 then folding side flaps 11 and 12 to form an envelope inserting a flexible magnetic recording disc in the envelope and folding and sealing a.