print cards on both sides

If you are designing the cards yourself, here is what to do:

1. Using some sort of graphics software, print your cards in a block (3x4 cards, or 2x5, or whatever is most efficient).

2. Center this block. That is, ensure that the block of cards is perfectly centered down the page. On any given software, there are tools that will help you achieve perfect "center-ness".

3. Copy the block of cards on a second page. Remove all the details from the cards, leaving only the outline of the cards. A vector-based graphic program like Photoshop or Coreldraw (or the GIMP, which is *free*) will be a big help here.

4. Fill the card outlines with your design for the backing. Remember: Copy+Paste is your friend!

The reason for centering the block of cards is so the backing lines up exactly with the original sheet of cards. Everything on the back must mirror the front. Do not cut anything until you have printed both sides!

A final warning: some printers will offset your image slightly to the right or left when printing. This is compounded when you print on both sides. A 1mm offset will separate both sides by 2mm! This is just ugly. If this happens, you will need to find another printer or compensate.

Is this worth the effort? It's up to you. Aside from the cosmetic benefits, a solid backing can conceal the flip side of a card held up to the light. This is especially a problem if you are printing with thin cardstock.

I don't know what kind of help you are talking about, so I can't help you there. Sorry!