I've been drawing maps for D&D since first playing the game in '78. Playing online requires digital maps, so I taught myself using GIMP.
Mountains are a Pain
When I was first learning to use GIMP to make fantasy maps, I used filters to warp and texture the land, which created a random, textured map that I used as a base and worked from there. It was all well and good when creating random maps, but if one wanted to make a custom map with specific features in specific places, the random method would not work.
The steps you go through to make a random map and a custom map are the same at first so I will gloss over the beginning and you can see how I do specifics in other articles I have written.
- Create a layer for Land and a layer for Water.
- Work on copies of these two layers.
- Build layer on layer so you can edit one without changing others.
- Use layers to create different versions of maps. (ex. Players map vs. DM map)
Setting a Base
To make mountains where you want them, you start with a solid base and then add layers of colors from dark to light. Dark being lowest elevations and light being highest.
- Start with a transparent layer.
- Fill in the land portion with a color. I use deep grey ( b3b2b2 )
- Lay in the base of the mountains with a soft brush ( bdc8b8 )
- Add more layers for a higher altitude. Each one lighter in shade the higher you go.
- With a thinner line, draw the crest of the mountain ( e4eae4 )
- Use a Gaussian Blur filter on the area with a blur radius at 15.
- Top off the crest with white with the narrowest brush . ( ffffff )
- Use Gaussian Blur again but with a 15 blur radius.
- Now use Filters- Distorts-Emboss... Play with settings until you like the result.
Note: Vary the thickness of the lines you draw with each color to add a variance to the contours of the resulting land mass.
Coloring Your Mountains
The next step in creating your fantasy map mountains is to add shading and color.
- Add a new transparent layer.
- Use a soft brush setting sized to match your mountains.
- Start with an off white color and about a 50% Opacity brush setting.
- Shade the lighter side of your mountains.
- Use a smaller brush and full white color to add snow to the tops of your highest mountains.
- With the same soft brush and 50 % Opacity you can add greens and tans to the lower levels where greenery would be... or a sandy beach.
Raising mountains under water is the same as on land.
- Light colors are higher so make the areas closer to land, lighter.
- Map the islands like they ar mountain tops.
- Deep water is darker.
- Make three layers one for texture, one solid blue and one white. Blue is the middle layer, texture is on top.