A-PDF Watermark Services is a windows services program which can run in the background to add watermarks to PDF files automatically. You can use the service to batch add text, image, graphic watermarks to existing Acrobat PDF files in sequence. A-PDF Watermark Services can watch multiple folders at the same time every few seconds, and process files in those folders instantly after detecting changing, it can watermark files automatically when the files are written into the specified monitored folders.