Balloon arches add a festive touch to weddings, birthday parties and other special gatherings. Though many people choose to purchase balloon arches from party stores, these decorations can be made at home. Making balloon arches requires a helium tank, but if one is available it can be less expensive to make a balloon arch at home than to buy one.

#### Things You'll Need

- Square of cardboard
- Tape measure
- Utility knife
- 2 colors of balloons
- Helium tank
- Large garbage bags
- Large rock or weight
- Fishing line
- Scissors
- 2 chairs

Lay a square of cardboard on a flat surface and draw a circle on the cardboard that is 8 inches in diameter. Cut out the circle with a utility knife. This will serve as a guide for balloon diameter, ensuring that they're all about the same size.

Determine the length of the balloon arch. There are several equations to determine a balloon arch's length. If the arch will be taller than it is wide, multiply the height by two and add the width to get the arch's approximate length in feet. If the arch's width and height are the same, multiply the height by 1.5, then add the width to the result. If the arch is wider than it is tall, simply add the height and width together to get the length in feet.

Determine the number of balloons needed for the arch, based on the length. The balloons will be arranged in clusters of four, and each cluster will provide 8 inches of length to the arch. To determine the number of balloons needed, multiply the length of the arch by 12 to get the length in inches. Then divide that number by eight to get the number of 8-inch segments required to make the arch, and round this number up, if it's a fraction. Multiply that number by four, and that's the number of balloons required. For example, an arch that is 8 feet tall and 6 feet wide would require 132 inflated balloons.

Inflate the balloons with the helium tank and check each one against the cardboard guide. The balloon should slide into the hole, with the guide fitting snugly around its midsection. Place the filled balloons in large garbage bags, sorted by color. Weigh down the edges of the bags with rocks or weights to keep the balloons from floating away.

Tie the balloons together in pairs by the knotted tails. Use balloons of the same color for these pairs.

Pick up two same-colored pairs of balloons and twist the pairs together at the knots to create a T-shaped cluster of four balloons. Continue to make clusters of four until all balloons are used.

Unspool a length of fishing line equal to the length of the arch, plus at least a 2-foot tail on either end, and stretch it taut over the backs of two chairs, suspending it in the air and securing the ends with rocks or weights. Rest the first balloon cluster on top of the taut fishing line, twist the balloons around the line and slide the cluster to about 2 feet from the end of the line. Repeat with a cluster of the second color.

Continue twisting balloon clusters on the fishing line, alternating colors, until all of the balloons have been attached to the line. Tie the tails of the balloon arch to stationary objects or weights that are spaced apart an appropriate distance.

- The result at the end of Step 3 follows from the following calculation: : [(8 x 2) + 6 ] x 12) / 8] x 4 = 132.

#### References

#### Photo Credits

- Karl Weatherly/Photodisc/Getty Images