Mar 15 2021 NIH requires the use of a font that is at least 11 pt in size and ... more than 15 characters per linear inch (including characters and ...
No more than 15 characters per inch including characters and spaces. descenders don't run into each other (will depend on font and size).
https://www.asdin.org/resource/resmgr/Research/Format_Details_1203.pdf
Adherence to font size type density
Type density including characters and spaces
Sep 1 2017 Font size shall be no smaller than 10 point and 15 characters per inch (Helvetica ... D. Animals: Estimate number
Jan 31 2011 font size of 11 points or larger. ... must be no more than 15 characters per inch. Type may be no more than six lines per inch.
problems with font size margins
Mar 31 2021 ... or Georgia typeface
Arial or Helvetica Font style 11-point font size. o Type density: Must be no more than 15 characters per linear inch (including characters and spaces).