Yeah they don't teach this way at schools, it would be weird seeing a panel sprayer etc using this method. I called bullshit on it until i saw my mate do it right in front of me. He has done several courses on panel spraying with marble paints and airbrushing so i thought i'd watch him.
He took a clean smooth piece of scrap metal, used some 600 grit (or thereabouts) paper, sanded in a circular motion, cleaned the steel off so it was free from metal filings etc, sprayed it in blue, mixed some weed killer (or those little balls you throw on soil for fertilisation, i forget which one) with warm water, covered the steel in the solution and let it dry outside for a while.
Then little crystals formed in the pattern he has sanded on the steel earlier. Then you lay paint of clear over the top. It was bloody weird i tell ya.