ink (n.) Look up ink at Dictionary.com
"the black liquor with which men write" [Johnson], mid-13c., from Old French enque "dark writing fluid" (11c.), from Late Latin encaustum, from Greek enkauston "purple or red ink," used by the Roman emperors to sign documents, originally a neuter adjective form of enkaustos "burned in," from stem of enkaiein "to burn in," from en- "in" + kaiein "to burn" (see caustic). The word is from a Greek method of applying colored wax and fixing it with heat. The Old English word for it was simply blæc, literally "black." Ink-blot test attested from 1928.
ink (v.) Look up ink at Dictionary.com
"to mark or stain in ink," 1560s, from ink (n.). Meaning "to cover (a printing plate, etc.) with ink" is from 1727. Related: Inked; inking.