To preview documents before printing, enable Preview on Ship in Printing Setup. You also need to have Adobe Reader installed.
When you Ship/Process a shipment, a preview of the shipping document or label appears in a separate window. The navigation buttons in the toolbar allow you to flip through the pages, if applicable, or magnify/reduce the preview. You may then click the Print button on this window to print the document/label or click the Save button to save the document as a PDF file.