inkstain

noun

1. A spot or area that has been discoloured by absorbing ink.

   “He was shabby and careless, with inkstains on the sleeves of his jacket, and his cravat was large and billowy, under a chin shaped like the toe of an old boot.”

   “She noticed, too, an inkstain on his right forefinger and judged that the daily grind of theme-correction was going on in spite of everything. - Cope, flushed and now rather tired, walked up stairs with his photographs, took a perfunctory sip from a medicine-glass, looked at the inkstain on his finger, and sat down at his table. Two or three sheets of a letter were lying on it, and he re-read a paragraph or so before dipping his pen.”