# Watermark > Add watermarks on your PDFs. ## How to use ```bash ./watermark.sh ``` You can watermark multiple PDFs by using the `find` command, such as : ```bash find ./folder -name "*.pdf" -exec ./watermark.sh {} \; ``` The watermarked PDF is named -out.pdf. The original one is not deleted. ## How it works First it creates the watermark in a specific file, then it exports the PDF in multiple PNGs, and watermark each extracted page, still in the PNG format so it cannot be then edited or modified (easily) using some PDF editing software. The script is pretty short and straightforward to read, you can adapt without much difficulties I believe. ## Additional notes This was part of a personnal project that wasn't supposed to be made public, so excuse the lack of comments and code dirtiness.