So why pencil versus china marker? Simply, pencil will give you a thinner defined line and the china marker a thicker heavier line.
If you are unfamiliar with china markers, they are a pencil that can write on a non-porous surface, like plastic, glass or metal and then can be wiped of with a firm rub with a dry cloth.
This is a sample I worked on in the acrylic inks class, layering up multiple different techniques.The thick white lines are textile paint, the thinner flower vine pattern in the center of the paisley is china marker.
The pencil does not penetrate the fibers like a gutta resist, so if you have a lot of ink on your brush and the fabric gets really wet it will bleed beyond the pencil lines, but the white lines of the drawn imagery will show through, which to me is the effect I really like.
I painted inside the flowers and leaves with red-violet ink to make them stand out more. The benefit of the china marker was that I could quickly add color without being too fussy and neat because it kept the ink fairly contained.