StampInStone is a handy tool that allows you to add or remove watermarks to any PDF document. The program allows you to add or remove image or text stamps, or both to your documents in just a few seconds. If you choose to stamp somr text, you just have to enter the desired text and select the font type, color, size and location on the document. The text can be placed horizontally, vertically, or diagonally, and then you can drag it on the document and select the exact location. The same happens with the image stamps. The image and text can be both underneath or over the document. Sadly, you cannot regulate the text and image opacity.
The program also includes batch-watermarking options which allow you to add or remove a text or image watermark from multiple documents at the same time. You just enter the input folder where the documents are located, and then choose an output folder where you want to save the converted documents. The application features a very simple and attractive user interface.
In short, if you are looking for a simple application to add watermarks to your PDF documents, StampInStone may be a good choice.