Design Nomenclature / Form & Geometry
Crown
Also called camber, tumblehome, panel crown
A slight convexity given to a surface that could have been flat — the barely perceptible bulge across a car door, a table top, a rolled panel. It exists because a nominally flat sheet reads as dented under a moving highlight, and because a crowned panel is stiffer than a flat one. Typical values are fractions of a millimetre across a span.
In practice
'Crown' and 'tumblehome' name the two directions in a body shop. Too little and the highlight breaks up; too much and the panel reads inflated. It is judged under a strip light, not measured.