Videos for making in-game map items unavailable

[Admiral Barrett]

Oh, I thought you were talking about map pieces.

Well that's easy. You'd just make a 300x300 image and draw it lined up to your map. The SOM grid is 100x100, so each map piece would be equal to every 3x3 pixels on the image. You can use the map files in the sample game as a reference to help you. Remember to save the image as a 256 color bitmap in your game's pictures folder.

I understand the principle behind this, but I am uncertain as to what drawing tool would be used. Are we talking about Paint.net, GIMP or something else?