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.
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.