I have been working on my campaign documents, which has included a section on maps, specifically a city map where the game begins. Through discovering the Lazy DM content on slyflourish.com I came across Dyson Logos maps, which are amazing!

In looking through their blog I found the following sections on creating maps with the following:

I scan it into Photoshop (used to use the Gimp) as greyscale at 600 dpi. Then I increase the brightness by +20, and the contrast by +40 to +60. This removes most marks except some pencil marks, and definitely kills the grid in all but the darkest graph papers.

I go around and try to white out any remaining blobs, blots, dots and dust on the scan. Then I use Photoshop’s “Stylize -> Diffuse -> Anisotropic” filter to clean up the edges. Then I reduce the dpi down to 300 to clean up any artifacts from the scan and it also reduces how unnaturally smooth the edges of each line are after the diffuse filter.