I'm using iTextSharp to merge a number of pdf files together into a single file. I'm using method described in iTextSharp official tutorials, specifically here, which merges files page by page via PdfWriter and PdfImportedPage. Turns out some of the files I need to merge are filled out PDF Forms and using this method of merging form data is lost. I've see several examples of using PdfStamper to fill out forms and flatten them. What I can't find, is a way to flatten already filled out PDF Form and hopefully merge it with the other files without saving it flattened out version first. Thanks