Often I get questions about what a stumper exactly is. A stumper is a rolled-up piece of felt paper with a point on both sides with which you can soften something. You can use the stumper on all kinds of erasable materials: colored pencil, graphite, pastel, and charcoal.
What do you use the stumper for?
You usually use the feather to blend colors into each other. I often use it myself to soften shadows..
How do you use the stumper?
You use it by rubbing one of the sides onto the paper. A tip: do this in a circular motion. This way, your work gets smoother.
Are the points dirty?
Use a sandpaper or nail file to file the tip clean again. If your tip is frayed, you can easily cut it, and with coarser sandpaper, you can easily bring the point back into shape.
It may be that the stumper returns the color on the paper when you use it again. Therefore, always clean it before using it on a new project or color. A tip is to use a stumper for every color, so you don't have to clean it all the time.
Many people use their fingers or cotton swabs in place of the feather. It is certainly possible, but I would not recommend it. Your fingers can be a bit greasy, so rubbing your drawing can cause very ugly and non-erasable stains. Of course, you don't want that. A cotton swab will work, but you can't use it over and over again. Which is very bad for the environment.