I built a document control system using workflow and smartforms in Sharepoint. After approvals, documents are published as PDF files. We are using a third party tool called Muhimbi to convert documents to PDFs. This tool adds watermark as well on PDFs.
Now we have a new requirement, certain documents based on some meta data, will NOT be printed as PDF, they will be printed in original format (Word or Excel). But we sitll have to print watermark in published documents. Muhimbi can only print watermark in PDF files. How can we accomplish in K2 workflow?
It seems there is no OOB way to achieve this but it should be possible by third-party tools or custom solutions.
Here are a few examples linked:
Maybe you can use a nother third-party watermark adding tool which supports batch-adding watermark. I think you can try Easepaint Watermark Expert, this software supports batch adding or removing watermark in images/videos/documents.