Here is a museum quality reproduction of the very scarce leather saber knot originally in 1885 for cavalry sabers.  In 1904 they were issued undyed instead of black, but the pattern was unchanged.  This sword knot was used until 1913 when Patton swords, with a completely different knot,  became the standard.

Our reproduction is the undyed 1904 version.  If you want to dye it for the 1885 version, be sure to clean off the tallow preservative on the leather surface before applying the dye.