What role does relief play in the practice of Backlapping?

The relief grind plays a major role in whether the backlapping process will be an effective tool to improve your cut quality. The reason is that the relief area on the reel blade provides a landing area for the lapping compound to adhere to. This enables the grit to be suspended on the reliefed area where it is then pushed and forced to pass between the reel and the bedknife, thus "effectively" removing metal. See illustration to the right.

On a flat ground or worn reel, the compound adheres to the back of the blade so when the reel rotates backward, there is very little grit that gets pushed between the two parts. Secondly, there is so much surface area and metal to remove on the reel blade that it makes the lapping process ineffective and time consuming. See Illustration to the right. The thinner the land area, the quicker the lap time and the more effective the lapping process.

Some people extol the negative ramifications of backlapping primarily because relief is needed on the reels to be effective. This has lead to claims being made that can be misleading. Facts are that backlapping can be an effective tool for maintaining high quality of cut standards, but must be conducted as intended.