Foam board is a good idea to use for making 3-dimensional craft objects. Foam board consists of 2 faces of medium stock Kraft paper sandwiching a core of polystyrene and is very sturdy, and yet very easy to cut and shape. With a razor cutter, it is easily scored and cut, although scissors have a hard time cutting it. Creating mountains with foam board is possible in either 2 or 3 dimensions. In 2-D, foam board can be cut, glued and painted in whatever way you wish. In 3-D, it can be stacked, shaped and painted. This how-to will explain both.
Step 1: Making 2-D Mountains
Start by tracing out the shape of the 2-D mountains you want to make. Use a picture or simply draw them from your imagination. When determining their size, consider their use. Will they be part of the background for a play, diorama or poster?
With their basic shape drawn, trace the lines with the razor cutter. Score through the top layer of paper. Go back over each line to cut through the polystyrene. Make a third cut to get through the bottom layer of paper.
Step 2: Paint the Mountains
Set the foam board mountains on newspaper or brown paper and start painting. Start with the base color of the mountains, whether it is white, gray or brown. Add more or less detail depending on how you plan to use or exhibit the foam board mountains. If you want, look at various pictures to give you some ideas of their colors.
Whatever the foam board mountains are intended for, after the paint has dried you can glue them into place.
Making 3-D Foam Board Mountains
Step 1: Cut Out Successively Smaller Shapes
Picture the layers of your 3-D foam board mountain like on a topographical map. The base is the biggest with each piece a little smaller. The shapes need not be even, but they need to get smaller as you climb higher so the mountain comes to a point.
Once the layers of foam board are cut, start with the base at the bottom and begin to glue the next biggest layer on to the one below it. Depending on how you place them, you can build ridges, drop-offs and flat spots on the mountain. By the time you get to the last piece, you should have a 3-D mountain built of successive layers.
Step 2: Smooth Out the Edges
The trickiest part of this will be to smooth out the edges of the layers of foam board. Your mountain will look more like a misshapen pyramid if you do not. Very carefully, pull the razor cutter from the top down after the glue has dried, scoring then cutting through the foam board to remove some of the edges. Don’t worry about dangling pieces of paper or foam. You can pull them off. Basically, you want to give yourself some smooth edges to paint.
Step 3: Paint
Once you are satisfied with the edges, you can now paint the 3-D mountain. Either use a picture or use your imagination. Paint the dominant color first followed by the secondary colors and let it dry.