Sunday, May 15, 2011

Carving rocks

My friend Jim gave me some  terrain boards which are too big and bulky for my taste.

So I'm cannibalizing them to make hills and other terrain features which are easier to store.

My friend Dave has asked me to show him how I carve rocks in terrain boards. So I figured I would throw up a quick little tutorial. I'm just using some cut off to show how its done. I will warn you as it does get a little messy.

The basic tools I use are......
  • Zip Knife
  • Stiff Brass Brush
  • Soft Brass Brush
So to make Sandstone or Limestone you start off making horizontal cuts along your foam using the zip knife. You then make a couple vertical or angled cuts against the grain.

Using the heavy wire brush you rub it along the horizontal to start removing the foam. Once you have a basic shape you use the softer brush to make the detail. If needed go back to the zip knife to make some more cuts. When you done this is what it should look like.
Once your happy with the look. Its just a matter of painting. I used a yellow ochre base followed by two lighter drybrushes. And this is the final effect.

To make shale or slate, you use the same basic steps but change the direction of the scoring. Your deeper scores will be on an angle with some lighter cuts perpendicular to the deep cuts.

Using the same brush technique as before you score the foam in the direction of the deep cuts. Followed again by the lighter brush to shape the rock. You can always add more cuts to change up the look. Also shale unlike sandstone breaks into small pieces, so run the soft brush on the perpendicular to create small breaks in the foam.
A simple coat of black with a couple drybrushes of grey. And you get.....

The key too is to look for colors that more closely match rock. I've used dark grey for the base color up to slate blue.

The final type is Granite or some other base rock. This is basically done with nothing but the zip knife. Start buy making cuts in every direction along the length of the foam. Some deeper than others.

Once you have your cuts, open the zip knife all the way and rub the blade across the foam. Don't be gentle, but don't snap the foam. ( like I did....) Keep working it until you have an uneven surface. Again, making cuts and rubbing as you go. Finally you end up with.....

I did a quick black prime with a couple drybrushes of grey and light brown.. But you get the idea....

I hope this offers some ideas for you to work on. Its easy to do and gives a nice appearence on terrain when you want a stone face on a mountain or something.

See ya.


  1. Amazing! I have always wondered how people have turned their foam into nice rock walls, and this offers a simple method of doing so. Thanks.

    1. I'm glad it helped. I've used this method for years. It does get messy but I think the effect is worth it.