Great, from what ive been told the finest stuff works as lubricant for plastic extrusions, in mixes with epoxy you should be able to use "bigger" stuff, it actually would be better (of how much i wouldnt know, the difference might be not butt-measurable).
Do a scrap trial first to see the "coverage", it should be the same of graphite, thats the proportions ill start with.
Btw it is inert but wear a mask and gloves.

Try a zebra pattern, polka dots, an "ink stain", wind rose, two arrows with written bow and stern, japanese symbol for water, water formula, beer formula?, the old native "men in canoe" drawing, "slippery when wet", "Pruden inside", "ARRRR... pur me a clap o' thunder!", " Keelhauled matey...", "Forgin ahead..", a beer bottle, a B&W reproduction of the "monna lisa",......, do not try a stylized fishbone, thats my logo