Start your basic search here:
http://tess2.uspto.gov/bin/gate.exe?f=searchss&state=3e7hlb.1.1
14 Records(s) found (This page: 1 ~ 14)
1140752
(1) TYPED DRAWING
REGISTRANT) Illustrator Pen Products, Inc
other
2060488
(1) TYPED DRAWING
IC 009. US 021 023 026 036 038. G & S: computer software for use in graphic design, desktop publishing, electronic publishing, printing, artistic and technical drawing, creating fonts and typefaces, and special graphical and textual effects; computer software containing clip art, and typefaces; and users' manuals and instructional books sold as a unit therewith. FIRST USE: 19861215. FIRST USE IN COMMERCE: 19861215
I am not a trademark attorney but have been involved in my advertising career with many and many companies. We typically had to follow strict guidelines when producing any product mock up.
If you will notice, it is not the word but how that word is used. If you were to take Adobe Illustrator, copy just the Illustrator part of the logo and pass it off as being your own, chances are you would get in big do-do over this.
I just happened to use that as an example as it is so well known but the second example above is actually Adobe's TM.