I made a square-sennet fob for my EDC Swiss Army knife, the idea being that having some 550 cord on hand at all times would be good. I got the directions from the thread on "Para-Cord Weaving". I managed to get about 7 feet of cord into a fob that's only slightly larger than the knife itself. To facilitate future use of the cord, I tied off the cord ends instead of melting them all together.

Then I had a thought: for ultra low-bulk carry, what about pulling the core out of the 550 cord and just carrying the sheath? Doug says that the sheath alone is rated at about 300 lbs test strength which would be adequate for most jobs. You would lose the functionality of using the smaller core sections as threads, but all PSKs are about compromise, and if bulk is a big issue then perhaps this compromise is worth it.

Thoughts?

I used to carry a similar one as part of my keychain. However, I have now found that the lighter my EDC is the more likely I'll have it on me. I reserve the PSK for when I'm conducting outdoor type activities and it has a good ten feet wrapped around it and a small loop with break away chain to wear around my neck. I find this is the most comfortable way to wear it and stays with me even when showering and sleeping.