flatness vs matte

flatness

noun
  • 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 

  • slim-tailedness or platykurticity 

  • The state of being bland : dullness 

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

  • The state of being flat 

  • The state of being two-dimensional; planar : planarity 

matte

noun
  • A decorative border around a picture used to inset and center the contents of a frame. 

  • The molten metal sulfide phases typically formed during smelting of copper, nickel, and other base metals. 

  • A background, often painted or created with computers 

adj
  • Dull; not reflective of light. 

How often have the words flatness and matte occurred in a corpus of books? (source: Google Ngram Viewer )