Imagine you are doing work on your car's engine and you are removing several hoses of the same size in the same area and you do not want to confuse them later during reassembly. When I was a kid, I remember my dad had a real small can of paint with a cap on the top (3 ounces?). When you loosened the cap, there would be a brush attached to the bottom side of the cap. Then, you simply marked the hose with a drop of paint and the device it attached to with another drop of paint. If you had multiple things to keep track of, you needed multiple cans of paint with different colors.

I needed to do this today so I went to the auto parts store. They said it sounded like a good idea but they did not have what I described. They suggested I use a Sharpie but I do not think that would work well. Instead, they suggested I use some touch up paint pens. This would probably work but at $6 each, not quite what I wanted. Then they suggested I use nail polish. I called home and my daughter said she had a bottle she no longer needed. Problem solved.

What do real mechanics use? Nail polish or something like what I remember my dad having?