In the days before TieWraps, cables were bundled using CableLacing (which resembles jumbo dental floss.)
An excerpt from an old Navy manual which describes how these cables were made is available at 
http://www.dairiki.org/hammond/cable-lacing-howto. (Thanks to ?GaryAllsebrook for scanning it, and me for HTMLifying it.)
Make sure you use waxed lacing cord. If you do not want to possibly damage wires then use lacing cord.
The content of this page is Copyright (C) 2000, 2001, 2002 Geoffrey T. Dairiki and
the other authors of the content, whoever they may be.
This is free information and you are welcome redistribute it
under certain conditions; see
http://www.dairiki.org/HammondWiki/opl.html for details.
Absolutely no warrantee is made as to the correctness of
the information on this page.