FinePrint makes it easy to access the double-sided capability of your printer if it supports double-sided printing. Even if your printer prints single-sided only, FinePrint can create double-sided documents by printing in two separate passes. You can configure your printer for double-sided printing in the Printers tab of the Setttings dialog box as shown here.
Settings can be manually changed if the printer capabilities are known. If not, click the Wizard button to start a sequence of tests to determine printer capabilities.