Polishing

Polishing is the abrasive finishing process that brings a material's surface to the highest degree of smoothness and brightness, reducing Ra roughness to sub-micrometre values through ultra-fine abrasive pastes, compounds or suspensions applied on soft supports (fabric discs, cotton mops, suede pads). Unlike sanding, which removes material significantly, polishing acts on the surface layer with a predominantly micro-levelling and thermomechanical action.

Machines include orbital or angle polishers for flat surfaces and bodywork, belt polishers for profiles and edges, and lathes for polishing cylindrical parts. The typical sequence involves compounds in decreasing abrasivity (cut, polish, finishing) to eliminate micro-scratches from the sanding stage and progressively reach a mirror finish. In the maker context, polishing is fundamental for precious metals, acrylic and 3D-printed resin, where the optical quality of the surface is an integral part of the finished product.