I recently bought a traditional cast iron wok from the Wok Shop in SF.
I seasoned it in the oven according to their directions. I'd like to
build up the black non-stick patina the pros talk about.

I've been using the wok frequently for several weeks. When I finish
stir frying, I find that when I wipe the heated wok out with oil and
paper towels, a black residue comes off on the towel. (I cleaned it
first with a soft sponge and water.) Is this black residue what is
destined to become the patina? Should I not try to wipe the inside of
the wok completely clean with paper towels? Is the black residue
harmful?

I've also seen seasoning suggestions which say the inside of the wok
should be wiped clean with paper towels. I'd like to hear any ideas
from the group.

Richard