Cool trick. I like the clear heat shrink. I picked up a Dymo labeler when I did the LS swap in the Jeep. That worked pretty good too for labeling individual wires. I tucked all those inside the loom.
One possible flaw with this might be the heat sensitive thermal printing paper - it's probably going to fade like your CVS receipts do over time. If you use one of those TZ tape type label printers though, it uses a thermal head but the lettering is much more permanent since it burns away material and splices it together with the background layer and a clear covering; these really do stand up to long term use. They also have heaps of different colour combinations too.
I just painted my MGB and labeled the wires with tape and of course we got primer on the tape. A better idea is to do what this guy is doing and if you are painting, cover the labels with tape, then after painting, take the take of and re wire.
