LTS -

You don't use a sharpie on the black stuff. You use "liquid paper" or "whyte out" - the white "correction fluid" you used to use to correct the typos when you actually used a typewriter.

Once it dries thoroughly it stays on almost anything reasonably well.

I still use it to mark all my wall warts so I know which one goes with what device, and it's great for highlighting those black-on-black connector labels on the back of the TV/VCR/DVD things so that you can tell who's what. Just paint the high spots, or put a smear on and then wipe it off of what sticks up.

If you want something even better, the acrylic latex art paint from the local hobby shop is also very durable (once dry) on most things, and you can get it in different colors and get a good tiny brush to put it on with. A $2 tube should last you a decade or two if you keep the cap on between uses.

John