CNC machining can leave a variety of finishes, depending on the tooling and cutting parameters used. Some common finishes include smooth or matte finishes, grooves, ridges, and textured patterns. The specific finish can also depend on the type of material being machined and the desired surface characteristics. Additionally, post-processing techniques such as sanding or polishing can be used to achieve a desired finish. Overall, CNC machining is capable of producing a range of finishes that can be customized to meet specific design requirements.