Things You'll Need
Foam sheeting or block
Black Sharpie marker
Did you know you could use foam sheeting like Styrofoam to create signs and sculptures? Here's how to make a Styrofoam sculpture in a few easy steps. You can preserve your sign or sculpture for longer use if you apply a layer of liquid latex to the surface after you've finished sculpting.
Start with a foam sheet or block that's deep enough to give you the look you want. For a sculpture, use a foam block. That will give you a three-dimensional look. For a sign, choose a sheet. Brush all loose crumbs from your block with a soft paint brush.
Use a projector to cast an image on your foam block or sheet. Use a felt tip marker like a Sharpie to draw the image on the foam. If you are confident in your drawing ability, freehand your image on the foam. Don't press down on the foam; you don't want to scar the surface.
Use a sharp, serrated knife, and cut the image out of the foam. Electric knives work great on foam. Don't force the foam; you could break your sculpture or at the very least scar it. Use a long knife to cut away big pieces and a smaller one to cut away more detailed areas. Be careful using your knife, and don't let kids cut the foam unsupervised.
Use your soft, clean paintbrush again, and remove the excess foam beads from off your block. Brush the front, back and sides of the foam. Then, if you've decided to go with a more textured look, use the side of the short knife to rub over the surface of the foam. That will create the textured stone look.
Next, use craft or acrylic paints and a sponge brush to apply the paint to your sculpture. Never spray paint foam. It will eat away at the foam and destroy your block. Dab the paint onto the foam. Do not oversaturate the foam, or you could jeopardize the integrity of the structure.
After your foam sculpture dries, use a wide, black felt-tip marker to outline your sculpture. This is a great way to redefine any areas you may have overlapped while painting. Don't use the marker if you are going for a more realistic look.