With the underside of the figure paneled, it was time to flip it over (allowing the bottom to dry) and paint panel lines on the green side. Astute observers will realize that, in addition to simply following the lines of the panels I painted on, I also sub-divided many of the shapes I had painted. The smaller panel sizes this creates increases the illusion of scale that I'm attempting to create. I also black-lined all of the sculpted panel lines.
For this lining process, I used a number "00" brush.
This is one of the only times I use such a small brush - it doesn't hold much paint, and you've got to be careful to not let what paint it does hold dry out while you work.
For the lines, I used a mix of black paint, black ink, and water. I mixed until I had something that would go on dark enough to use just one coat, and was easy to control (I didn't want it to bead up or flow all over the place).
Once I had finished lining the green side, I moved on and repeated the process for the belly of the ship.
I saved myself some time by making the panels on the bottom of the ship slightly larger than the top. This meant that I had fewer lines to paint. It's important to stay fairly close to the size of the topside panels, though, if you don't the ship could end up looking a bit off.