The best way to protect your work, and to show everybody who is responsible for a particular image, is with a watermark. To add a watermark in Gimp, we use the Text tool and the layers controls.
Let's see how to work with it by adding a simple watermark to an image. The first thing to do is choose the text. For my example, the text will be Allan Brito.
So, we select the Text tool and click on the image. It will make a dialog box open, where we should type the text:
If you want to change the Font and Size of the text, just use the Text options in the main window:
Now we can make the text transparent. To do it, just select the text layer, ...