First pass on page 3 color. Click to enlarge. Below, I will try to keep things brief and I will fail.
I finally downloaded the Flatten and Multifill Photoshop plugins. Survey says... not a magic bullet, but they probably sped things up a little bit and definitely produced cleaner, more line-conformant results. In case you're curious, here's how they work:
The plugins are easy to install -- just drag the files into Photoshop's plugins directory and they'll show up under "Filters." There's only one tricky step - the black and white line art (not black on transparent, mind you) must be completely de-anti-aliased (re-aliased?) before the plugin will work. It turns out that this is done by selecting Image->Adjustments->Threshold. Bump the slider a bit to the right until all your lines connect, and then run Multifill. Multifill automatically fills every closed area in the drawing with a unique color.
Next comes Flatten, which removes all the black lines from the drawing and smooshes all your color patches against one another so their jaggy borders meet up underneath your lines. You end up with this:
I stared at this way too long when it was first generated. It's like Mister Toad's Wild Ride for your eyeballs. I soon discovered that there were some areas where color had leaked (see the bottom-middle panel), so I had to go back a couple of times to tighten up the drawing (in the future, I will be much more conscientious about closing my outlines). Then began the arduous process of "flatting" -- that is, turning this patchwork of gobbledygook into areas of like color. After fifteen hours of hunting down leaf edges and little dangly bits, I ended up with this:
I didn't think too hard about my color choices at this early stage -- the idea is to set things up so that you can easily select objects in the scene and adjust their color later. To start, I just went with green for trees, blue for skies, and purple for people (of course). But back to that fifteen hours: does anybody know if there's a way to click-and-drag with the magic wand? If there is, I couldn't find it. The closest I could find was the Quick Selection Tool, which creates anti-aliased edges (very bad). Man, if I could have clicked-and-dragged those leaves, this would have taken two hours instead of fifteen. This whole process definitely convinced me of the need to outsource my flatting.
The flatting plugins produce one unexpected bonus: if you paste the multifill patchwork into your top layer, knock down the opacity to 9 percent, and set the blend mode to Soft Light, you get automatic variation in areas of repeated detail. I may someday look back on this trick with disdain (can you say "lens flare?"), but for now it seems like a really nice way to get big masses of leaves, rocks, or planks to look variegated. Not too shabby!
A couple of people have asked me what kinds of brushes I use in Photoshop. I use the default Brush Tool settings: normal mode, 100% opacity, 100% flow, 100% hardness. At my current image size, the 4-pixel width works best for intricate linework, while thick outlines get the 7-pixel treatment. Should I be using something more high-falutin'?
In other news, Brandon Graham has a new King City book on the stands. It's great.