Yeah Ian's nailed it above for you mate
Another thing I've found is with using the candies over chrome gives a nice anodised effect, just worth noting that whatever you use to back it over with will have a dramatic effect with candies & chrome being transparent.
As for Backing with nitroblock & enamels, leave the wb paints to cure off overnight & mist the nitroblock or enamel on in light coats & build it up