Key Card size: 3 3/8" X 2 1/8?? Standard credit card size CR80 X 30 Mil Special For Inkjet Printers (normal PVC cards will not absorb normal ink from an inkjet printer). These cards are for use with inkjet printers that have a PVC card tray. You can print on both sides of these cards.   Direct printing using tray for epson printer.They could be used for PVC Plastic Cards,Membership Cards,Educational ID Cards,Employee ID Cards,Promotional Cards and ect.  You could start printing directly on PVC ID using your existing Epson L800 T60 P50 T50 R230, R270,R280, and ect. with Dye inks (standard inks) and pigment ink, that makes your printer life last longer.