Knife Sharpening by Mors Kochanski
This is a training booklet that applies to all walks of life, including the sharpness of the knife one chooses to use in survival. The time taken to master knife sharpening is highly variable. Once you know what to do the fast learner takes about 4 accumulated hours to put a shaving edge on his or her knife the first time, after which it takes moments to re-establish your edge.