Burnishing edges on vegetable tanned leather can be done in many different ways. I have tried several different methods but have come up with my own idea. Putting fine grid sandpaper on a dremel sanding drum. It was not possible to find a sanding band with a finer grid than 400 so I had to make my own.
Using high quality duct tape wrapped around a sanding drum mandrel you can stick your sandpaper to the mandrel. Surprisingly the sandpaper does not come off very easily.
In this case i use a 400 grid sandpaper. This is not for burnishing but for sanding the edges prior and during the burnishing process. For the actual burnishing I'll use 3000 grid.
The duct tape and the sandpaper are cut to the correct width. The duct tape should be able to wrap around the mandrel at least two times. The sandpaper should be a little longer than the circumference of the mandrel. It will be cut to the correct length once it is stuck to the duct tape.