I liked the effect, but I didn’t want the tedium of having to do all n steps manually next time I go to use it. So, I wrote a GIMP plugin script to do it.
Here is an example of the plugin script in action. As you can see, I started with a text layer and a selection that was bigger than the text layer. The plugin uses the selection size as original edge of the paper (original, as in before the paper was burned).
And, here is the resulting image:
Here is the Burnt Paper plugin script. Plop this in a directory that’s in your script search path and refresh GIMP’s scripting and then you’ll find it in the
Filters > Decor menu. [You can see the script search path by going to
Edit > Preferences and selecting
Folders in the left sidebar. And, you can refresh the scripts by going to
Filters > Script-Fu > Refresh Scripts.]