Could anyone share a successful specification sheet example for a Mangin mirror to go out for quote?  I have the toleranced radii and center thickness, edged diameter and clear apertures all defined, calling out wedge across clear aperture to be less than 25µm, polish quality, AR coating on the refractive surface, etc. all complete.  What I don’t know is how best to specify the reflective surface.  I know the desired reflectivity, which will likely either require aluminum or silver, but I’m not familiar with how to specify the protective coat(s) that is/are applied on top of the reflective coating.  Is flat black epoxy paint OK, or can it oxidize the coating and cause delamination?  Does an intermediary non-oxidizing, adherent coating need to be applied over the reflective metal before painting flat black?  Thanks for any advice.  Mike