Gimp tutorial -Make a fancy border around a (rounded corners) image
Gimp tutorial on how to make a fancy border around an image with rounded corners or rounded edges. The same method can be used for text in GIMP. I’m using stroke the path in Gimp because that gives the best results. If you stroke the selection it doesn’t look as good.
You can also stroke with dotted lines in Gimp and stroke with paint brush tools.