The Collaborative International Dictionary of English v.0.48:

Lettering \Let"ter*ing\, n.
   1. The act or business of making, or marking with, letters,
      as by cutting or painting.
      [1913 Webster]

   2. The letters made; as, the lettering of a sign.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Letter \Let"ter\ (l[e^]t"t[~e]r), v. t. [imp. & p. p. Lettered
   (-t[~e]rd); p. pr. & vb. n. Lettering.]
   To impress with letters; to mark with letters or words; as, a
   book gilt and lettered.
   [1913 Webster] letter bomb

WordNet (r) 3.0 (2006):

lettering
    n 1: letters inscribed (especially words engraved or carved) on
         something [syn: inscription, lettering]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "lettering":
   Italian hand, Spencerian writing, block letter, bold hand,
   book hand, chancery hand, copperplate hand, coup de plume,
   cryptography, cursive, cursive hand, engrossment, epigraph,
   initialing, ink spilling, inkslinging, inscription, law hand,
   longhand, macrography, majuscule script, micrography,
   minuscule script, pen, pen-and-ink, pencil driving, printing,
   round hand, scrivenery, scrivening, secret writing, text hand,
   transcription, transliteration, typewriting, typing, uncial,
   writing