I've used Dyneema
whipping twine from Marlow, 3/64" diameter. Comes in all the bright colors.
But the pull tab is silly, IMO-I only do it if it's asked for.
On a shackle diameter that small, you might just use #4 polyester whipping twine, if you can find it braided, not twisted. The colored Dyneema
comes in sizes rather large for that.