Things You'll Need
Several large cardboard boxes
3 tubes of very strong adhesive (like an epoxy)
When you think about fences, most likely the image of a whitewashed, wooden picket fence or a wrought-iron gate comes to mind. You can use another sturdy material to make a fence--cardboard. It is true that cardboard is by no means waterproof or strong enough to be used in an outdoor fence. But if you have a school play or an indoor display planned and you need a quick fence, don't shell out cash for wood. Cardboard is cheap, easy to work with and biodegradable.
Lay down the painter's tarp in your large work area. Cut the boxes along their edges and separate the pieces. Stack them into a pile. The number of boxes you will need depends on how long you want your fence to be. The top and bottom pieces and very short sections can be discarded (or recycled).
On one long piece of cardboard, draw a 6-foot long, 6-inch wide rectangle. On top of that rectangle, draw a 6-inch wide, 6-inch tall equilateral triangle. The shape should now look like a large fence post. Decide how long you want your fence to be and how many fence posts you want to make. You will need two fence posts for every foot of length in your fence.
Cut out the first fence post that you drew. Use that post as a stencil and trace the remaining number of posts you desire on the rest of the cardboard pieces. Cut out and stack the remaining fence posts into a pile.
Cut out two 6-inch wide strips from the remaining pieces of cardboard the length of the entire fence. If you do not have any pieces long enough for you to cut out strips of that length, cut out four strips that are each half of the intended length of the fence.
Lay the strips that you just cut down on the tarp. The strips should be laid out horizontally and should separated by about 4 feet. If you had to cut four strips then place two strips end to end and place the other two under those end to end. Carefully glue the fence posts on top of these strips, one next to the other, until you have filled the fence with posts. Allow the structure to dry.
Since this is going to be a life-size fence, you will need refrigerator-sized boxes. Get as many boxes from large appliances as you can find. Large department stores and electronics stores are always throwing out boxes of this size, so it pays to ask if you can take them off their hands. If you want a smaller fence, you can always cut the cardboard fence posts shorter. Or you can cut them taller. You can make the fence as long as you desire. You can even cut the cardboard slats into different shapes or leave them rectangular. You can also paint the fence if desired.