These desert-stepped hills where created using a rotocast machine. Since these machines are on the pricey side, we decided to build out own rotocast machine which was a fun project in itself. The reason for a rotocast machine, is that it allows you to use less plastic, creating a hollow model. We decided to go a step further and backfill the hollow void with expanding foam. The end result made these hills very light and ridiculously rigid. You could throw one on the ground and it won’t break. At most it would just ship some paint.
We created 7 different stepped-hills from the smallest one which you see here on the left, to the largest one which you see here at the bottom right. Each step was designed to make sure minis would balance nicely. The masters were made by layering foam and applying joint compound. Once the joint compound is almost dry, we used a larger wire brush to achieve the weathered strata effect. This is a very easy and satisfying technique.