Green’s Dictionary of Slang

1. (orig. US) to sign a contract.

1940		Pittsburgh Courier (PA) 17 Feb. 7/1: Duke Ellington has inked a new dual year contract with William Morris.
1958		Mad mag. May–June 20: Had I inked it, I would snag the bit.
1998		Source Nov. 74: Cash Money Records, who’ve inked a $30 million distribution deal with Universal.
2004		Winnipeg Sun 18 July 🌐 Darryl Wolski has scored another potential knock out for his upcoming Hockey Gladiator slugfest. The Brandon promoter has inked a deal [...] to carry the double knock-out hockey fighting tournament.
2021		J. Ellroy Widespread Panic 85: ‘Anita O’Day and Barbara Payton have inked contracts’.

2. to take fingerprints.

1977

A. Brooke Last Toke 211: We gone have us a pair once we ink up you jive ass fingers!

3. (US) to tattoo [ink n. (7)].

1991		D. Gaines Teenage Wasteland 109: I’m introduced to a guy who’s freshly inked. Percy has me examine the grim reaper [...] on his musular arm.
2009		J. Stahl Pain Killers 62: Not one part of me believed Tina could have feelings for the inked-up skeck I’d glimpsed.
2013		J. Stahl Happy Mutant Baby Pills 132: Inked as they were — they were all inked up — only Nora had that German shepherd, baring its fangs.
2013		D. Whish-Wilson Zero at the Bone [ebook] Riley favoured Japanese tatts, and his long arms were inked from neckline to wrists with dragons, demons and cartoon samurai.