Today I offer you an improvised knife sharpening tip. Improvised means it is not as good as a normal method of using a whetstone or other sharpener, but that it will work in a pinch.
If you take a ceramic coffee mug or bowl and flip it upside down you will notice a ring where there is no glaze.
It is possible to use this ring to sharpen your knife blade just as you would use a ceramic sharpening rod.
I have tried this, and it does leave residue on the ceramic ring, and it does sharpen the blade.
I would not use this for one of my high quality knives, but when out camping and I have to sharpen my knife “Right Now”, then this is a good idea to keep in the back of your mind.
Hopefully this can help you in the future.