Hi,
To print on both the side either your printer should support duplex mode or you need to manually set from printer settings.
I found below code from
Here[
^]
crxreport.PrinterDuplex = crPRDPHorizontal
And for your second question, Yes you can print 2-3 cards from single page. it is the similar thing like you are printing multiple rows in a page. hope you got hint from this.
Thanks
-Amit Gajjar