Styrofoam is a trademarked polystyrene product manufactured by the Dow company. The blocks are lightweight, versatile materials that are used for a variety of craft and home improvement projects. Styrofoam is often cut and painted to form landscaping for models, as well as used to create items such as covered headboards for beds. In addition, smaller Styrofoam blocks are good cushioning for packages. Cutting Styrofoam blocks can be accomplished with basic cutting tools.
Lay the Styrofoam block on a flat work surface. Use a ruler or tape measure and a marker to draw lines on the Styrofoam where you want to cut it.
Slide one of the marker lines over the edge of the work surface until it hangs off by at least 1/2 to 1 inch.
Place the sharp tip of a utility knife at one end of the marker line block and position it almost perpendicular to the Styrofoam. Move it lightly across the entire marker line to cut down 1/4 of an inch into the Styrofoam. This creates a guide cut which will make cutting through the rest of the block easier.
Pick up the knife blade and return it to the starting position. Angle the blade downward so that it creates a deeper cut. Move the blade through the original guide cut that you made the first time.
Continue making at least two more cuts through the Styrofoam block until only a 1/4 inch layer or less remains intact. Extend the blade of the utility knife as needed as you cut deeper into the Styrofoam.
Place one hand on the outer edge of the section of Styrofoam that you are removing. Place your other hand flat on top of the Styrofoam still on the work surface. Press down on the end that is hanging over the table to break it off.