Oh my! How did I ever live without THIS?! I have no idea! It's a WHITE pencil lead, made out of something else besides "lead" which isn't white. Here, try the French: CRAYON CRAIE PORTE MINE EXTRA FINE. (You got the "extra fine" part, right?)
Don't worry about what it's called. Know that the mechanical pencil is top of the line, and the stuff inside is fantastic for marking on dark colors. You can see the line and you ALWAYS have a sharp point. Comes out after you've stitched through it, or they come out with water. They can also be erased off the fabric. As with all markers, play it smart and test them on fabric you wish to use them on first.
I love this thing! ENJOY!