Quote Originally Posted by Midgardsormr View Post
To get the interior of the country to be transparent, I used the blending mode. Each blending mode uses different rules for what it makes transparent. In this case, I used "darken," which causes any pixels in the selected layer that are lighter than pixels underneath it to become transparent. Since white is lighter than everything, all the white will vanish when the layer is set to darken.

Conversely, if you fill the country with black and set it to "lighten," you'll get the same result--lighten turns pixels transparent if they're darker than what's underneath.
Here we would fill the country with white and use "multiply". Also, I've never done a map for a publisher where the glow was not set to be the same size everywhere. Just FYI.

-Rob