The furniture industry uses gradations starting at 40, and in the case of solid wood, up to 2,000 – in the process of preparing for high gloss polishing. In the grinding process, it is important that the jumps between successive gradations are not greater than the value of the currently used gradation. For example, if you apply paper gradation of 120 immediately after using paper gradation of 40, grinding will not bring the expected results, because we are unable to wipe the deep scratches in a reasonable time.