What Car? Q&A: July 2009 - Paint confusion
A) Solid or flat paint is the same thing. It's the cheapest option when buying a new car, but your colour choices will probably be limited.
Metallic paint contains tiny flecks of metal, which makes it sparkle under light. It usually costs extra (between £300 and £2000), but highlights the contours of a car's body better than a solid colour.
Cars with metallic paint are generally worth more on the second-hand market, too.