11 MATERIAL, SUPPLIES, AND DEVICES FOR USE IN PRINTING BY HECTO-SPIRIT PROCESS-NAMELY, HECTO-CARBON PAPER; PAPER SUITABLE FOR RECEIVING MASTER IMPRESSIONS FOR FUTURE TRANSFER BY HECTO-SPIRIT PRINTING PROCESS; AND SPIRIT MASTER UNITS EACH COMPRISING A SHEET OF MASTER PAPER SUITABLE FOR RECEIVING IMPRESSIONS FOR FUTURE TRANSFER BY HECTO-SPIRIT PRINTING PROCESS WITH A SHEET OF HECTO-CARBON PAPER FACED TO THE BACK THEREOF AND ADHESIVELY SECURED TO THE MASTER SHEET ALONG ITS UPPER EDGE WITH THE MASTER SHEET PERFORATED ADJACENT THE AREA OF ADHESION