"Why hand grinding and polishing? In a world of CNC machines, 3D shaping printers and mills, why would anyone need to work by hand? Advanced technologies require inflexible fixturing. Working by hand means your fingers become those fixtures. Intuition is the adaptable program used to reach the specified goal. Hand grinding and polishing is the most basic process for turning raw glass and crystals into a prototype to be copied for production. When producing one or a handful of parts, its often less expensive to hand grind and polish than to create the fixtures and tooling for production. That doesnt mean its always easy, but 10th wave flatness and 10 second parallelism are quite achievable by hand"--.