Gaspare, As I understand it the X-Ray Fluorescense technology is a non-destructive method to determine the composition of an item. Something like spectroscopy, with the idea behind it being that the physical/elemental/chemical composition of items made 70 plus years ago should not have modern period substances in them and should generally conform to what was used in the target period. A long while back having seen results from a more traditional spectroscopic examination of period dagger blades that set a sort of benchmark that was compared to U.S. standards. Something that the "Chapagne" decals/paint failed because of the presence of copper. With the airbrush vs. decal IMO another matter entirely. With, as I understand it paint, an airbrush, and templates used in lieu of decals which are paint like transfers on paper which is discarded. Both having the same overall appearance after drying. With Best Regards, Fred
PS: Not having seen one for confirmation - I made the assumption that XRFacts themselves are the COA's that are being sold to 'authenticate' the "Champagne SS helmets".
