flatness

The state of being flat

The state of being two-dimensional; planar : planarity

The state of being bland : dullness

Mattness, the quality of a painted surface which scatters or absorbs the light falling on it, so as to be substantially free from gloss or sheen

(oenology) Lack of bouquet and freshness of a wine, through too much aeration or infection with film yeasts

(statistics) slim-tailedness or platykurticity