Whether you are making a fake cake for a stage prop or building a giant cake for someone to jump out of at a party, you will want the cake to look as real as possible. You will also need some idea of what type of cake you want to create. Look through magazines or cookbooks to find inspiration before you start to build.
Paper and pencil is all you need to make a diagram of your fake cake. However, your diagram must be detailed, including measurements for each section of the cake. To create your diagram draw the cake as you see it first, then break the cake down into parts on paper. For example, the circular section of the top layer, the side strips of the top layer and the colours used for the layer should all be marked with measurements and colour schemes. After creating the diagram you will have a guide to show you exactly what you need to do in order to complete the project.
For the simplest fake cake use cardboard. Cardboard is easy to cut and shape and is inexpensive. Draw out each section of the cake on the cardboard, cut it out and glue the pieces together with white, clear-drying craft glue.
You can also shape your cake with papier mache by using chicken wire to make your cake form, then applying strips of newspaper dipped in one part white glue and one part water over the chicken wire. After applying three layers of newspaper over the chicken wire let the glue completely dry before you decorate.
You can also find styrofoam discs or sheets in a number of sizes that can be decorated to resemble a cake.
When making your cake out of cardboard you will need scissors and/or a utility knife for cutting. Although a box cutter is cheap and easy to find, it may get dull quily if you are cutting a lot of cardboard. A carpet utility knife has extra blades and is more sturdy. If you are making your cake out of papier mache you will need wire cutters to cut the chicken wire. Wire cutters used for faux floral designing are sufficient and can be found in the craft section of the fabric store.
Unless you want to wait for days for your fake cake to dry, don't use oil based paints -- always acrylic. For a small cake, a 59.1ml bottles of acrylic craft paint will suffice. For a very large cake use acrylic house paint. Acrylic paint dries within a few hours and is easy to clean up with soap and water. Once your cake is painted try caulking applied with a caulking gun to the edges of the layers to look like frosting applied with a decorator's tip. Use plastic figures attached to the cake form with glue and painted as desired for other decorative flourishes.