A lot of the cameras I use from the 70s to 90s have fluorescent paint in the number or markings on the lenses. I decided to use neon paints to make numbers easier to read on some old lenses, or simply upgrading their looks. 1- I used Ikea Mala paints because they're cheap and come in 5 colors that will react to black light (pink, orange, purple, green and yellow) for less than $10 and have a needle point bottle. But you can also use any acrylic paints. 2-Daub paint on the numbers or letters you wish to paint after putting some tape to cover other areas, avoid making bubbles 3-Scrape excess paint with a piece of cardboard (like a business card, which is flexible). Wipe the other areas either immediately with fingers or qtip or wait for it to be dried to chip it off 4-The painted glyphs will now be more legible under low light and pop out under black light. Here, the orange paint I used very closely matches the one that was the manufacturer used on the zone focusing markings: Yo