Adding a watermark to your photos with Inkscape discourages others from using your work without permission. Here's how to create a watermark with Inkscape version 0.92.4 for Windows, Mac, and Linux.
How to Make a Watermark in Inkscape
Any watermark information you place on a design can include your name or other identifying information to indicate that the artwork is not free to use. Your watermark should be large enough to be noticeable, but transparent enough to allow your artwork to be seen. To apply watermarks in Inkscape:
Open the image you want to add a watermark to in Inkscape.
Select Layer > Add Layer. Placing the watermark on a separate layer makes it easier to move or modify it later.