Run to the hills!

Line-of-sight-blocking terrain has always been important in 40k. Back in the early 90s I built a big polystyrene hill, which is usually a central feature of my battlefields. It's made up of three separate sections, so it's quite flexible, though I do usually just use the full version.

However my battlemat (from Urbanmatz.com) is double-sided. I've been using the Badlands side as that's very flexible, but this green hill really doesn't work for the Desert side. Hmmm...

I found some inch-thick sheets of polystyrene languishing in a box in the garage (I never throw this kind of stuff away if I can help it) and after hacking it around (pinning the rocky outcrops with cocktail sticks and gluing everything together with PVA) assembled this:

I then attacked the rather-too-clean lines with a rough knife, creating a horrible mess and a more realistic-looking hill.

Polystyrene is (obviously) really weak. My fifteen-year-old self hit on the idea of covering the earlier hill with a mix of paint and sand (about 50-50, so a pretty stiff mix). I added a large dollop of PVA to the mix for good measure and a scattering of gravel to represent fallen rocks. After a rough spray with the remnants of a can of black spray, I arrived at this stage:

Once dry, this was now resistant to damage (and rather heavy too). I now needed to blend it with my desert mat. I applied rough coats of Burnt Sienna acrylic then a lighter drybrush with Yellow Ochre whilst the Sienna was still wet so it blended in nicely.

I considered leaving it at that initially, but decided that those rock formations needed to be more, well, rocky, so painted them black again and drybrushed up with grey and then white

It didn't really take all that long to do and now I have a hill for the desert!