To get the best performance out of your Japanese knives there is processes that go beyond the normal sharpening that is normally needed. Thinning of the overall thickness of the knife is often done after repeated sharpening. With repeated sharpening the cutting edge moves into thicker and thicker material. This results in reduced cutting performance because of the increasingly thick steel. This is when you would want to have your knives thinned. We price our thinning service from $20-$60 depending on how much work is being done. Light thinning is $20 , medium thinning $30 , heavy is $60. If your knife has heavy damage such as large chips medium to heavy thinning is usually recommended. The price of thinning is on top of the sharpening charge fore example a knife getting a medium thinning and sharpening would total to $45 , $12+$30.