SMALL CARDS: 8.5cm x 5cm One Side. There are online resources that make it fairly easy to upload your design and create his referral card and special offer. They are cheap to print. If you want a second side you will need to add the Back Side information yourself using the printers' design tool. Or simply provide a PDF file in the color of your choice to your regular business card printer and have them print this on the back of your card. They are already formatted to meet the requirements of a standard size business card including crop marks.