One of the most festive party decorations is the balloon. You can use balloons alone or in attractive configurations to add to the colour theme of a party. To make the surroundings look a little more upscale than just single balloons, you can make a simple balloon arch. You must fill the balloons with helium instead of plain air. The helium holds the arch upright so you do not need a rigid structure for the arch.
Inscribe a circle on a piece of cardboard for a balloon template. Any size will do, but 8 or 10 inches is a good place to start. Cut out the circle and discard the round part. The cardboard with the circle cut out of it becomes your template.
Cut a length of nylon monofilament string, otherwise known as fishing line, for the arch spine. The Signature Balloons website gives you a way to estimate how much monofilament string you will need. If you want an arch that is taller than it is wide, multiply the desired height by 2 and add the desired width to get the length of monofilament you need. For an arch wider than it is tall, add the height and width together. For an arch about the same width as it is tall, multiply the height by 1 1/2 and add the width.
Tie each end of the monofilament to a piece of heavy furniture. Move the furniture apart so that the monofilament is fully extended and taut. Leave it in this position so it is easy to attach the balloons in the following steps.
Put a balloon on the nozzle of the helium tank. Hold the circular cardboard sizer template around the balloon and inflate it until the sides of the balloon just touch the template.
Tie off the balloon by hand at its neck as close to the round part as possible. Leave as much neck extended as you can.
Tie the balloon onto the extended monofilament with the untied neck portion. Pull the knot firmly but not extremely tight. You can also use twist ties or extra pieces of the monofilament to attach the balloons to the line. You may want to move the balloon later to adjust the look of the arch.
Inflate as many balloons as it takes to fill the arch. Leave about 12 inches between balloons if you want a simple arch of a single line of balloons. The space between balloons should be the same over the entire arch. Gently slide balloons to get even gaps if you have to. You can tie several balloons together for each spot if you want a fuller balloon arch.
Tie the ends of the monofilament to balloon weights instead of the heavy furniture. Place the weights on the floor the desired width apart in the area where you'd like the arch to remain. The helium will hold the arch up.
When the balloons are in place on the monofilament, tie curling ribbon to each balloon neck to make the arch look even more festive.