moiré vs mottled

moiré

noun
  • A fabric, often silk, which has a watery or wavelike appearance. 

  • A pattern that emerges when two grids are superimposed over one another, sometimes unintended or undesirable in many applications such as in weaving and screenprinting. 

verb
  • To give a watered or clouded appearance to (a surface). 

mottled

adj
  • Colored in patches; spotted. 

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