DIY Projects & Crafts Birthday Party Crafts Rainbow Balloon Arch Here's how to make a showstopping rainbow of balloons! At your next celebration, this decoration doubles as a colorful backdrop for photos. By Martha Stewart Editors Martha Stewart Editors Facebook Instagram Twitter Website An article attributed to "Martha Stewart Editors" indicates when several writers and editors have contributed to an article over the years. These collaborations allow us to provide you with the most accurate, up-to-date, and comprehensive information available.The Martha Stewart team aims to teach and inspire readers daily with tested-until-perfected recipes, creative DIY projects, and elevated home and entertaining ideas. They are experts in their fields who research, create, and test the best ways to help readers design the life they want. The joy is in the doing. Editorial Guidelines Updated on April 23, 2020 Share Tweet Pin Email Amp up your party décor with this festive DIY. This idea comes from our friend Kathleen Ballos. While there may not be a pot of gold at the end of this rainbow, we're sure you'll love it just the same. What You'll Need Materials Balloons in rainbow colors Balloon pump ($3.49, target.com) Cardboard Craft knife ($11.99, michaels.com) Pencil String Packing tape Electrical tape Instructions Draw an arch (almost like an upside-down "J") onto the cardboard and cut out (our version is approximately 14 inches wide and five feet tall.) Depending on the size of your cardboard box, you may have to cut the cardboard into pieces about 14 inches wide and use packing tape to form an arch. Add a piece of cardboard to the bottom slightly wider than the arch (this will be the cloud). Start adding the base layer of balloons. To do this, blow up the balloons with the pump, tie, and tape to the edge using electrical tape. Line the entire edge with red balloons, varied in size for scale. Fill the remaining cardboard with the remainder of balloons to complete the base layer. To cover any gaps in the base layer and add depth, inflate small-sized balloons. Use electrical tape to stick them in place. Add white balloons onto the bottom to form the cloud in the same way. To hang, use packing tape to attach a loop of string to the back of the rainbow and hang from hooks/nails on the wall.