If you want a flat paint job, you need the paint AND the clear to be flat. spraying a flat clear over a glossy color would still make the color look glossy, and only add an extra layer of protection. Just think of how the gloss black would look without the clear and thats about the same outcome you will have when you spray a flat clear over.
Check out all the badass flats that House of Kolor offers. Metallics, pearls, all kinds of colors. I like the twilight black metallic myself.
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