Plainess or Plainness: How To spell?
The word Plainess is misspelled against Plainness, a noun meaning "The quality or state of being plain."
Plainness has double "nn" is mispronounced as "n"Remember double 'NN' in between the strings plai & ess which should not be misspelled with single 'N'
Wrong Spelling:  plai-n-ess  Correct Spelling:  plai-nn-ess 
Find more wrongly spelled words of Plainness to spell it well.