Once your card is completed, save it (right-click and "Save image as ..."), insert the image in a word processor, and ajust its size (width of 6.3 cm). Print it and glue it on the back of a real pokémon card. More information
By default, your cards are private. To make public your card, use the section Publish in the public gallery. This section appears on your right only if the image and the name of your card monster has been changed.