The OSTtoPSTAPP PDF Watermark Tool refers to adding watermarks to your PDF files. Watermark can be used to add a company logo or other branding to a PDF file, which can help to promote brand recognition and professionalism. A Watermark identifies the owner of the documents and includes important information such as contact numbers and website links. Watermarks can be used to discourage the distribution of sensitive or confidential documents, as they can make it easier to track down the source of any leaks. If we add a watermark on a PDF file it can be used to protect copyright on PDF documents, as each watermark can be unique to a specific recipient or version of the documents. Users can also change the position or opacity of the watermark. Users can create a unique effect. Watermark can be created using PNG, JPG, and TIFF images only. Install the free demo before using it.