speckle vs stipple

speckle

verb
  • To mark with speckles. 

noun
  • A small spot or speck on the skin, plumage or foliage. 

  • Kind; sort. 

  • A cluster of interchromatin granules in a nucleus. 

  • The random distribution of light when it is scattered by a rough surface. 

stipple

verb
  • To use small dots to give the appearance of shading to. 

noun
  • The use of small dots that give the appearance of shading; the dots thus used. 

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