Knowledge and quality
In machine polishing, a polished surface is obtained by "smudging" the material and thus obtaining a smooth surface.
Thus, one can increase the surface's reflection and obtain gloss.
A method that is poorly suited when high demands are placed on the surface layer as material from abrasive tape and polish is baked into the surface.
If the additive is used, it should be exactly the same quality as the base material.
Differences in shade in gloss may otherwise occur.