Whats the best way of using body paint to turn from a white man into a black Zulu and how much would i need?

Im trying to dress as a Zulu for a party and need to become black. I want to be able to sit down without leaving a black imprint. Can anyone help?Whats the best way of using body paint to turn from a white man into a black Zulu and how much would i need?
no human being is 'black'. try getting some dark brown body paint, often found at sex stores lol