Many modelers like to use rigid foam insulation as a base for their model railroad layout landscape. While the best foam to use is that made specifically for the purpose by Woodland Scenics, or foam made for building architectural models, some modelers will use the white Styrofoam "beadboard" insulation. Like the architectural foam, beadboard is best cut with a hot knife, and it can't be carved easily into irregular surfaced shapes. The most popular solution is to use the less expensive blue foam insulation made by Dow or the pink foam insulation made by Owens Corning.
There is a series of "how-to" videos by Everett on YouTube about sculpting this kind of insulation:
- Part 1
- Part 2
- Part 3
- Part 4
- Part 5
- Part 6
- Part 7
- Part 8
- Part 9
Note: In these videos Everett simply paints the foam insulation. As a fire safety precaution, and to seal the surface for painting, foam should be covered with plaster cloth or a coating of plaster thinned so that it can be applied with a brush. This will, however, affect the texture of your scenery.