ink vs sign on

ink

verb
  • To sign (a contract or similar document). 

  • To apply a tattoo to (someone). 

  • To apply ink to; to cover or smear with ink. 

  • to eject ink (sense 3) 

noun
  • Tattoo work. 

  • Publicity. 

  • Cheap red wine. 

  • The black or dark-colored fluid ejected by squid, octopus etc, as a protective strategy. 

  • A pigment (or dye)-based fluid used for writing, printing etc. 

  • A particular type, color or container of this fluid. 

sign on

verb
  • To join something, after signing. 

  • To begin broadcasting a radio or television signal, usually at the beginning of a broadcasting day and after being off the air for several hours. 

  • To commit oneself, as to a project, a goal, an organization, a cause. 

  • To apply to receive unemployment benefits. 

  • To log on; to start using a computer, radio, etc., or to start talking. 

noun
  • The time of day when a radio or television station begins broadcasting, usually after being off the air for several hours. 

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