A little more detail on what I did this time:
1) After putting 4-5 coats of black spray paint on the axe head, and letting it dry for a few days, I drew the design on in pencil. Then I used my dremel stylus to carve the paint off the drawing... leaving bare metal where the etch was to be.
2) For the actual etching I went more with how dougelder did it, see his posts on the mod'ing trailhawk thread. I submerged the axe head in etchant in a Pyrex cup. I didnt agitate much. I let it sit for a couple hours, took it out, rinsed off, re-submerged and let it soak another hour, rinsed, soak for a final hour for a total of 4 hours soaking. I dont think the precise time periods are significant, I only make the point that it soaked for hours and I rinsed a couple times. Paint held up well but you can see that the etchant starts to eat under the resist; notice how the points of the leaves are blunted and some of the weaving lines were starting to overlap. Glad I didnt leave it overnight! However, I liked the depth that was gained from such a long soak. For finer detail and a shallower etch probably a soak of less time. I liked how this depth allowed for the browning solution to create a pleasing contrast in the end.
3) On the browning. Birchwood casey Plum Browning. Simply followed instructions on the bottle, using oven set at 300f to get the head hot enough to sizzle & pop the solution. Took ~ 6 applications to get the color where I wanted it. After applying the solution I would let it cool, then carded, then re-applied the solution to a re-heated axe head. Carded with steel wool and this nice Klingspor fine Sandflex hand block I bought online. A rough towel or denim cards ok, too, but not for the first rough initial coats. I tried oiling it after but that just made the whole thing black and the etching indistinct, so washed that off right away.