As a member of the species Homo sapiens (subsp. dominoensis), I very rarely venture into Neanderthal territory. However, today I have come to receive enlightenment about an edict issued by a prominent Neanderthal Elder, David Charlesworth. On page 33 of Volume 1 of his book 'Furniture-making Techniques', he states, without giving reasons, that his "ruler trick", which I use all the time for producing a micro back-bevel on plane irons, "must never be used for chisels".

In fact, I use a slight modification of his ruler trick for chisels - I lower the back-bevel's angle to only about 1/3° by resting a point on the back of the chisel about 3" (rather than the 1 1/2" that he recommends for plane irons) from the chisel's edge on the ruler while honing a short (about 1/16" long) back-bevel on the chisel. According to my trigonometry, this ensures that the resultant edge of the chisel is displaced from the plane of the back of the chisel by only about 4/1000ths of an inch. In my view this causes no perceptible detriment to the performance of the chisel. But it certainly speeds up the sharpening process immensely.

So, can a Neanderthal guru tell me what, if anything, is wrong with my ignoring the Charlesworth Edict?

David