I have covered how to make mountains and valleys in previous article. You now have to start working on your rock outcroppings and vertical cliffs. You should have built their basic location into your mountain/terrain design-Nooks for rock outcroppings and the structure for vertical cliffs. If you didn’t there is nothing stopping you from adding them now you just need to be more creative. You can add some more plaster cloth on top of what you have in a way to create more vertical surfaces or to create a natural nook for a rock outcropping.
I always liked making plaster casts of large rocks and placing them around the layout as I needed. Nowadays you can buy them ready made. I have done it the old fashioned way and made rubber molds from some cool rock features out in the garden. Each mold around 6-8 inches in diameter. You buy the mold making material and follow the directions by applying a bunch of coats to the surface you are molding. My rubber molds are a bit more flexible than the store bought type which is good and bad. I use 2 techniques for rocks. Pour the plaster in the mold and let it set. Then plaster or glue them into place around the layout in different combinations and orientations. The second is to only let the plaster set half way so that it is still flexible in the mold. Then quickly invert the mold onto the mountain surface you wish the rock detail to appear. If you ever put a 5 gallon water bottle on top of a water cooler you replicate that exact concept here. Once inverted, press the mold down and around the contours of the mountain. Do not squish out all the plaster you want it to be in the mold taking on the mold’s “look”. Once hard but not completely set you can peel the mold off. What you did was leave all the rock “look” from the mold but contoured it to the mountain you made. So now you can have a limitless amount of different rock/cliff shapes with only a few molds. For large rock faces just overlap each mold. There will be a seam however you can either carve the plaster to make it look like to rocks fracturing together or hide the seam with vegetation/vines/weeds. By the way it’s always easier to carve the plaster before it’s completely set.
When all your rock work is done and dry a few days you can then stain the plaster to the color of your liking. Get yourself some acrylic tubes of paint. Some greens, some browns, and a black. Squirt a dime sized drop into a plastic cup of water and mix well. Then cut a sponge to fit the cup. Please practice on some plaster that you will be painting or covering with ground foam first. Sponge on the darker colors then right on top of them while still wet the lighter colors. The plaster soaks in only so much stain so you have to get a feel for it. Use some real life examples and try to replicate the colors. Darker in the crevices lighter in the weather exposed surfaces. It actually is easier than it sounds.
You can purchase all sorts of readymade rocks and rock sheets. Depending on your layout and the look you are going for some of these products will be perfect for you, none of them are cheap if you need a lot of them. You will have to figure out how to blend them into your layout so they don’t look store bought and out of place and the plaster technique I describe above is a great way to blend them in.
