You can convert "All pages" or just "Custom range".
Click "Set Watermark" icon to enter into "Watermark" interface:
Check "Applying Watermark" option, you can choose default stamps, Edit them, or Add Text Watermark, Add Image Watermark, Delete, Move Down/ Up.
There 5 types of Page Quality and Size for you to choose.
If your PDF files contain Table of Contents, check this option to enable Flip PDF to import them to the output page-flipping eBooks;
If your PDF files contain links, check this to enable Flip PDF to reserve them in the flipbooks;
Check this option to enable the Search feature in created flipbook so your readers can search content with keywords.