in ink

in ink

In pen, as opposed to pencil. The teacher says that we're not allowed to do our math homework in ink. You need to sign this in ink—here's a pen.
See also: ink
Farlex Dictionary of Idioms.

in ink

written or signed with a pen that uses ink, not with a pencil. You should write your report in ink. You must sign your checks in ink.
See also: ink
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • pen and ink
  • in pencil
  • pen up
  • ink in
  • pen in
  • to hand
  • mark (someone or something) with (something)
  • mark with
  • much ink has been spilled
  • over
References in periodicals archive
"The decision to specialize in ink production marks the true birth of the 'Siegweierk' brand," said Siegwerk CEO Herbert Forker.
During that month, the Israeli military carried out a campaign of mass detentions in the territories, holding over 1,000 Palestinian men in a week and etching ID numbers in ink on some detainees' arms.
Gravure is a process wherein a printing cylinder that contains an image area comprised of a pattern of tiny holes (called cells) runs partially immersed in ink. The ink fills in the cells, and excess ink is scraped off the OD of the cylinder by a blade.
But the more rapid delivery of the ink onto the substrate has necessitated changes in ink formulations.
"OEMs have typically locked in ink sales through bundling 'tie-ins' with machine servicing," said Mr.
SOY-BASED INKS - soy oil and other vegetable-based oils are a promising replacement for some of the volatile petroleum products used as vehicles in inks. "Soy-based inks are better, but you still can't eat them," one designer says.