Henceforth, the options for creating natural looking territorial borders seemed to be as follows:
  • Figure out how to draw your own and make them look natural.
  • Generate a bunch of squiggly lines, hope they lie near to where you want them to be on your map, and then clumsily bucket fill them in.


Neither of these options are satisfactory IMO. I know roughly where I want my borders, I just suck at making them look natural (wiggly and not uniform.) So, I figured out a way to turn my smooth, blob-y hand drawn borders into jagged natural looking borders using Photoshop.

Here's my map with borders before wavifying them and here it is after. You can add less or more or different amplitude waves than me, that's just what worked for my map. Also as a bonus I added instructions for styling the territorial borders three ways at the end: Thin Lines, Inner Glow, and Color Overlay.

Here's the full tutorial.

It seems long, but it goes over every single step. The summarized steps are pretty simple:
  1. Import your map and a black and white representation of your continents. Make a land outline selection channel from your black and white map.
  2. Use layer masks over colored layers to draw the territories, and use a layer mask of your land outline selection channel to keep them within the lines.
  3. Make a new layer from visible, and apply the Wave filter a few times to make the borders wiggly.
  4. Layer mask the wavy layer, and reveal the parts from your drawn territories that you don't want to be wavy.
  5. Use Select Color Range and convert all the territory colors into shapes.
  6. Wala! Now you have natural looking borders which you can style a thousand ways.