The blade of your knife should be extremely strong, easily resharpened, and capable of holding a fine edge. If you can touch it to your throat and draw blood, whack it against a frozen deer bone without rolling the edge, and pound the tip 2 inches into a tree trunk at a right angle to the grain and stand on it without breaking it, you've got the prerequisites of a woodman's knife.
In addition:
# The blade should be as long as the width of your palm, with the metal extending the full length of the handle.
# The back of the blade should run in a straight line with the back of the handle and be wide and flat so that it can be used with a baton (a stick used as a hammer).
# The cutting edge should curve gently from tip to guard to facilitate sharpening, with the point falling in line with the center of the handle. It should also have a flat grind (hollow-ground blades bind when driven into wood). Serrations have no place on the blade of your knife-they can't be resharpened easily and the occur on the part of a blade you need for most detail work.
# A small, lower finger guard is acceptable but not necessary. An upper guard is an abomination, interfering with placing the thumb or forefinger along the top of the blade for control.
# The but should be flat and durable enough for you to pound on.
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