The AreaLabeller allows 'smart' labelling of area features. It takes area size into account and sets label heights proportionally. The algorithm is simple - square root of feature area divided by N makes the label size equal to one N-th of the square, which size is equal to the size of the feature. In the case of states or counties of the United States it makes very nice picture. However, this transformer is not well suited for labelling areas stretched along meridians, such as Chile.

Another 'smart' feature of this transformer is its ability to place labels along latitudes, which often gives nicer look to maps.