We need help of the collective mind of the forum. Researching effect of chopping boards on edge longevity, we came across the phenomenon of improved sharpness as we sliced edge-friendly chopping boards http://knifegrinders.com.au/SET/Chopping_Boards.pdf To see if it was something about the factory edge, I re-sharpened the knife used in our chopping board experiment at the same 16 dps, using our sharpening and deburring procedure for mainstream stainless steel knives. The edge angle was controlled with our computer software for Tormek, and verified with a laser protractor. The only difference was that I started on #80 CBN wheel to remove the metal affected by factory sharpening, and then followed our standard procedure on CBN wheels #200, #400, #1000 and deburred as described on our website http://knifegrinders.com.au/06Procedures_SS.htm The edge scored 80 BESS, so I had to bring it to the initial sharpness of the knives used in the experiment which was 120 BESS - I did it by rounding the apex by gently honing it on the rock-hard felt wheel with 1-micron diamonds on Tormek at 2.5 degree higher than the edge angle, till the edge started scoring the same as the knife in the experiment. Then I tested the low-density polyethylene board the same way we did with the factory-sharpened knife. If you ask me why i did not use the best edge-friendly high-density polypropylene board - I avoided extremes on purpose as I wanted to look further into the phenomenon of self-improved sharpness as such. Following are the sharpness data and chart. We see that the re-sharpened and cleanly deburred edge also gets sharper from slicing the chopping board due to this mystical phenomenon, and sharper than the factory edge. We see that it is not plastic specific, and not about the burr. I am still scratching my head for a plausible explanation of this phenomenon. Comments are welcome.