How do I flatten a PDF so that the elements Ive added in PDFpenPro are not editable?
Choose Print from the File menu, and then click Save as PDF. The resulting file will not be editable in most PDF viewers. It will still be editable in PDFpen 3.X / PDFpenPro 3.X and later versions, because these versions allow you to edit any images in a PDF file, including ones that have been added by PDFpen and PDFpenPro.