Watermark

A hidden watermark to protect your photos.

First, create a watermark: File->Create->Photo Watermark

To Use:

1. edit your image
2. save your original edited image
3. apply a watermark: Images->Filter->Render->Photo Watermark
4. change opacity of the watermark layer and/or erase visible parts
5. save and upload your protected image

To View Watermark

1. open you original edited image (background)
2. open the image to be verified
3. layer mode to grain extract

Original

Protected

After grain extract

After Colors->Auto->Stretch Contrast

Full tutorial at:
http://www.gimpdome.com/index.php?topic=5971.0