A template is the 'pattern' that FastEnvelope uses to print a correctly sized and barcoded envelope on your printer.
A template consists of the envelope's heigth and width, its top and left margin, its name, and some additional printer information such as the paper size and rotation.
To print #10 Business Envelopes, choose the template for #10 Business envelopes; for Postcards choose a postcard template.
To select a template, pull down the Templates menu and make your selection. The Envelope window will change to display your selection.
