"No smears, no small ink pools, just effortless writing."
(Ad for a pen.)

Also occurs as a verb:
"you can clearly see the dark shadows, usually where the ink pools at the end of a line"
http://peninkcillin.blogspot.com/2014/03/diamine-grey-ink-re...

Oh, here's an example even from typography, not calligraphy or pen-writing:
"The 2002 redesign of The Wall Street Journal adopted Frere-Jones' Retina face for its stock listings -- a font that clips out tiny corners where legs of letters meet, like the crook of a K, to prevent ink from pooling up and making the tables unreadable."
http://usatoday30.usatoday.com/news/nation/2007-09-15-143857...