Bryan: I took black paint and a slightly beat up natural bristle brush, and caught the brush on the edges so that it sorta flicked over the surface, giving it the conical pattern with some stray edges...kinda hard to describe.
VF-18S: No pens here. I did all the lines with a mixed up super dark grey paint/balck ink mix, painted them in with a synthetic brush, and used a cloth to wipe away any excess towards the tail so it would just add to the weathering.