I tied this Spanish/woven ring knot around one of my Shields of Strength pendants with ungutted paracord. I'd tried smaller diameter cord first, 1.4mm and 0.9mm tries, but the pendant didn't want to stay centered with the narrow knot work, so I went with paracord for this project.
I used a 1/2"/12mm split ring to fit around both the pendant and the knot work, and still have room for the ball chain covered with gutted paracord.
I had tied a 3 lead Turk's head knot first, around a cap from a butane lighter refill can, since it was about the same diameter as the pendant, then moved that knot to the pendant, adding the split ring, then worked in the Spanish/woven ring knot pattern, staying inside the split ring, tightened it up, trimmed and melted the ends to finish.
I also tried the Round Brocade Knot(Coin Wrap), following JD's(TIAT) instructions from his most recent book, Paracord Project Inspirations, but the curved/convex/concave shape of the pendant, being different from a flat coin, was testing my patience, lol.
The wrap is snug around the pendant and stays in place, but it could still be forced out/removed, so a coat of super/krazy glue could be added to the knot to make it more permanent if desired.
And an example shown of 0.9mm cord, tied into a Gaucho knot variation, used on the Shields of Strength Battle Shield pendant that I keep on my EDC keyring. If you tie a knot that's wide enough to fit/form around the outer rim of the shield and tighten it up in place, smaller diameter cord can work, it just takes a bit more patience.
I started with a 3 lead 8 bight Turk's head knot, raised/expanded that into a 5 lead 14 bight knot, then worked in the Gaucho pattern.
As with the paracord wrap, I used the butane refill canister cap as a mandrel first, then slid the knot off the cap and around the pendant where I gradually tightened it up over several passes as I used a finger/thumb on one hand to shape the knot around the edge of the pendant, and a clay stylus/improvised marlinspike with the other hand to work out the slack. I added a coat of brush on super/krazy glue to finish. I used around 4 feet of the 0.9mm cord in the finished knot.
And the pendant shown with a small neck knife on a ball chain with kydex sheath.