Surface preparation decides what a part looks like in the hand. The same machined housing can be bright, matte, grained or reflective — and only one of those will match the rest of your product.
Sequence matters
Blasting and brushing are usually performed before anodizing or coating, because they set the base texture that shows through. Polishing is often the last step before packing, on parts that stay bare. On tight-tolerance parts, polishing happens before final machining so that the material removed does not affect the fit.
Consistency across assemblies
Directional finishes are applied in one direction per part so a set of panels or housings reads consistently when assembled. Send a sample or a photograph of the target appearance, plus a note on which surfaces are visible, and the process is planned around that.