There are a few different scissor blade geometries as there are knife edges. Commonly one side will act as an 'anvil' ( look for a very steep chisel grind) and the other does the cutting ( a chisel cut monofacial edge.) In actual use both will wear and require truing things up. Fine sandstone is abrading the edges. Paper is wearing the blades dull. Why? Think what paper is made of and what cutting up our survival fuzzsticks, shelter poles, grizzly bear spears and coconuts does to the knife we chose after reading the measured, unemotional knife discussions at ETS <img src="images/graemlins/tongue.gif" alt="" />.