this is an easy one coz i did it on my old vento 1, scotch cloth your bonnet 2, spray with matt black 3, rollor on the chalkboard paint 4, leave it to dry for at least 7 hours before writing on it Easy as that. Chalk board paint can be bought online or i think wicks sells it to. you need to rollor it on to get it right as its too thick to spray. I have some here as i'm doing my roof in a few weeks time if your local pop over and we'l do your bonnat at the same time.