Sorry for the bad english. No I dont mean on the tyre wall, but the tread itself. When at concours you take the wheels off for a good clean the tyre tread also must be nice black. But this must be at a safe way because after the show you will have to drive the car home.
So what stuff can you use for this?
Tyre foam would be best as it will get everywhere - but no way would I drive a car on the road with anything like that on the tread. Can only have one or the other my friend !