I.R.I.S. Readiris 14 for Mac User Guide - Manual (Page 58)

Readiris TM 14 – User Guide
53
To select the font type:
 On the Settings menu, point to Font type.
 The font type is set to Automatic by default.
That way, Readiris recognizes "25 pin" or "NLQ" (Near Letter
Quality) dot matrix, or other "normal" printing.
 To recognize only dot matrix printed documents, click Dot
matrix.
Readiris will recognize so-called "draft" or "9 pin" dot matrix printed
documents.
Character pitch
The character pitch is the number of characters per inch in a
typeface. The character pitch can either be fixed, in which case all
characters have the same width, or proportional, in which case the
characters have a different width.
To select the character pitch:
 On the Settings menu, point to Character Pitch.
 The character pitch is set to Automatic by default.
 Click Fixed if all characters of the typeface have the same width.
This is often the case in old typewriter documents.
 Click Proportional if the characters of the typeface have a
different width. Virtually all fonts in newspapers, magazines and
books are proportional.