The Comm Guild Maelstrom's Edge

Terrain Tutorial: Rocky Outcrops.

Posted on Thursday Sep 12, 2019 at 05:00pm in Tutorials

- by Iain Wilson

Buildings are all well and good, but sometimes you want to get out of the urban sprawl, and wage apocalyptic war surrounded by nature! I've shared articles previously covering alien forest bases made from silicon aquarium plants and cactus clumps made from foam balls, but this week we're tackling the ever-popular stacked rock outcrops.

These rocky terrain features are made from sheets of expanded polystyrene. I've used pieces cut from an old foam vegetable box here, because that's what I had laying about. You can generally buy expanded polystyene by the sheet in various grades and thicknesses from hardware stores or foam specialty stores, but if you're more thrifty-minded it's worth asking your local fruit and vegetable retailer if they have any old boxes laying around, or you can save the packaging inserts from electrical equipment.

Expanded polystyrene is composed of loads of small balls of foam pressed together to form a sheet. For this sort of project, you want polystyrene composed of relatively small beads (under 2mm), as the larger sort is much harder to cut cleanly and is more prone to damage.

The first step is to cut a piece of foam to form the base of the outcrop. This can be whatever shape you like, just remember to leave one or more flat spots for the stacked rock spires. For cutting the foam, you can buy heated wire cutters specifically for the purpose, but generally a sharp knife will do the job - just don't use the good kitchen knives, as cutting foam does tend to blunt the knife fairly quickly.

Next, cut rocks for the stacks, starting larger and making each successive rock a little smaller, for however many you want to stack up. Rocks come in all sorts of different shapes and textures, so the actual shape here isn't too important, but I like to use largely flat cuts to create a faceted look. Avoid making really sharp edges on the foam, as these will be fragile. Make your rocks different thicknesses, and you can angle the tops a little to avoid the stack looking too artificial.

Once you have your rocks cut, glue the stacks in place with PVA glue. Don't use superglue or plastic cement, as these will melt the foam. For a little extra strength, you can push toothpicks or wooden skewers cut to an appropriate length down the centre of the rock spires. Push this in until it is sitting just below the surface of the topmost rock, and then glue a scrap piece of foam into the hole to plug it up.

Now we need to disguise the foam a little, as just painting over the foam with regular paint tends to look like, well, painted foam.

So instead, paint the outcrop with a textured paint. Again, the specific texture is more or less up to you depending on the look you want, but here I'm using a Dulux 'River Rock' textured paint. This is an acrylic, indoor house paint with a fine sand texture mixed through it. You can generally pick up sample pots of similar paint from hardware or paint stores, or check out their clearance bins for mis-tinted paving paint, which you can sometimes grab for cheap. If you can find a colour that you want to use as a base colour (as I've done here) that's great, but otherwise you can just paint over it, so the actual colour of the textured paint isn't too important. You can also just use regular paint and stir in some fine sand - silversand (sold in pet stores) is ideal for this.

Dab the paint on with an old brush, rather than brushing it. This avoids brushstrokes and helps to clump the texture. The paint I'm using takes two coats to build up the level of texture I wanted for this outcrop, but coverage will vary depending on the paint you use.

To add some visual interest, glue some sand and/or small gravel to the top surface of the base of the outcrop with PVA glue, and once the glue is dry, undercoat with a similar colour to your textured surface - a few shades darker or lighter is fine, once again just depending on the look you want.

Finally, choose a lighter colour and drybrush over the whole thing. Here, I've used Army Painter Ash Grey, as it's a nice, pale grey with a slight brownish tinge, so it ties into the textured basecoat nicely. If you're unfamiliar with drybrushing, you take a large brush, dip it in your paint, wipe it on some paper until there is hardly any colour still coming off, and then brush that over the surface to be painted. With so little paint on the brush, it just picks up the raised detail, leaving the base coat in the crevasses. You can slowly build up the colour in this way until you get the level of highlighting that you want. It's a great technique for painting rough surfaces like rocks or fur, or for getting worn metal effects.

The finished outcrop, ready for the table:

You can glue your outcrop down to a piece of hardboard to give it some extra weight if you wish - this can be a help in preventing it from sliding around the table!

Keen to give it a go? Be sure to share your creations, or ask any Maelstrom's Edge- or hobby-related questions on the Comm Guild Facebook page!

You can pick up the entire Maelstrom's Edge model range, including our plastic urban terrain detail sprue in the webstore here.

For other Maelstrom's Edge modeling articles, including tutorials and walkthroughs of a wide range of different building and miniature projects, check out the Hobby section of the Maelstrom's Edge website here.

Find the Maelstrom's Edge rules and the full range of models at

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