I would use two scripts. If you have FMPA you can set up a "Print" menu. Set up one script for printing ID cards and specify the printer in the Print Setup script step. Set up another script to print whatever gets printed on your general printer. I use a few printers and have set up a situation whereby printers can be assigned dynamically, but it's a complicated process that uses shell scripts and completely bypasses any Print Setup or Print commands. Filemaker would do well to develop a dynamic printer capability.
What OS are you using?
Sorry for the omission- I am using OSX and FileMaker Pro 11.
Have not been able to find examples of printing scripts... if I set up my Printer and Page Layout - then build the script - will the script inherit the print attributes from the OS?