I have 6 synthetic brushes and two of them are Yaqi tuxedos a 24 and a 30mm and I can confirm the fibers are defo different on the black. The softness overall is a combo of softer tips and softer fibers in their full length. It has backbone but not as much as the Yaqi tuxedo. More than a APshave cashmere and near identical to an APShave tux. The caveat that as reported the Yaqi tux's backbone is not from the amount of the fibers, the thickness of fibers or the tensile strength of the fibers, IMO its drawn from its clue bump.