Car window marker / paint

[ford12]

Hi All
What kind of markers do people use for writing for sale signs on there cars ?

Thanks

[Morexbs]

The thinner paint pens last longer on the glass and usually have to be scraped off but they are harder to read from a distance.Car auction companies use them to write lot numbers and other stuff on the windscreens.
The bigger,thicker ones can usually be rubbed off with your fingers but are easier to see because you can write much thicker.