In addition to tracing black, I’ve also used Fusemaster high-fire enamel and Glassline paints. I’ve rubber-stamped with them, but see no reason why they wouldn’t also work with a pen. The tracing black and enamels can also be mixed with lavender or squeegee oil, as well as clove oil. Vent your kiln when firing.
To prevent smearing of oil-mixed paints, either let dry thoroughly, or pre-fire the painted pieces to about 1200F before assembling your piece for fusing.