I have a careful 6 month long project I've been working on fabricating a computer case mostly from aluminum, and now it's down to the surface finishing. The carbon steel stand I would like to get plated in a black chromium / black nickel / black chrome. I've heard these terms thrown around colloquially, so I assume they go hand in hand for the same thing. I've so far sanded the stand with 220 grit sandpaper, wearing latex gloves so no skin oil contaminates it. I'm hoping to get this to a professional to have plated, do I have everything covered that would need to be done for that or should I do anything else? Maybe I'm over preparing and they will take care of the rest?