How to add a watermark

WPS office software could be compatible with Microsoft Office, and these training contents help students or home workers finish their work efficiently.We often see unique watermarks printed on the back of some files. Adding a watermark can not only prevent others from embezzling but also can help us to indicate the source of the article. So how can we add a watermark to a document?To show the source, we need to add the watermark of WPS Academy to the following documents now.1. After cl....