If you are making a model for a school project or a train set, you can make the model look more appealing and beautiful by adding on walls that looks like real rocks. You can make a fake rock wall with a few materials that can be found at a craft supply store, such as plaster of Paris and textured paint. Once finished, you can place the rock walls into your model to make it look more realistic.
Fill a spray bottle with warm water and add in 1 teaspoon of liquid dish soap.
Spray the inside of a rock wall mould using the soapy water.
Pour 1 cup of powdered plaster of Paris into a measuring cup and add in 1 cup of warm water. Mix well with a spoon.
Pour the plaster of Paris into the prepared mould and allow the plaster to set for about 1 hour.
Pop out the fake rock wall mould and place it onto a flat surface.
Paint the wall using grey textured paint. Let the paint dry.