Making paper trenches is an inexpensive way to replicate trenches for small battlefield models and dioramas. Using common craft supplies you may already have at home, you can create an entire system of miniature trenches. Papier-mache creates a realistic textural surface similar to built-up terrain.
Cut a 4-inch-by-4 inch square section of Masonite, foam board or cardboard, using a mat cutter and a craft knife. This will be the trench base.
Cut a 4-inch-by-1.5-inch rectangle of cardboard. As an alternative to cardboard, you can glue craft sticks together, edge to edge, to the same dimensions. Glue the 4-inch edge of the cardboard or bottom craft stick to the base, about one-third of the way in, to make a trench wall. Make papier-mache while waiting for the glue to dry.
Tear newspaper into 1-inch-wide strips.
Mix equal parts flour and water into a bowl to make a paste. Coat the newspaper strips with the mixture and ball them together to resemble clods of dirt.
Build up papier-mache at a 45-degree angle from the short side of the trench base up to the top of the trench wall. Allow the newspaper to dry thoroughly before continuing.
Sand the papier-mache to create your desired texture, if necessary.
Paint the papier-mache, trench wall and base with brown acrylic paint and let it dry.
Coat the entire model with craft glue.
Sprinkle dirt and sand over the glue for a realistic texture and appearance.
Make as many trenches as you like and place them end-to-end to make longer trench systems.