A principle to keep in mind is that whatever you have on the machined finish will remain after anodizing or chromate conversion. Think of the anodizing process as similar to film development. Whatever is in the substrate of the aluminum will be more visible after the anodizing process is completed.
Anodizing or chromate conversion cannot hide machine marks, scratches, extrusion lines or dents. Our etch process (depending on alloy used of course) can remove tiny scratches or fine lines but the more pronounced the mark or scratch the more likely it will show after finishing. We do offer acid etch (for an extra cost) that will help hide some of the machine marks and lines by creating a matte finish.