In Japan, families make and fly carp-shaped wind socks called koinobori for Children's Day on May 5. Our version is made out of a recycled Tyvek envelope (often used for overnight shipping).
Download and print our fish template. Cut the envelope open and lay it flat, blank side up, on a table. Trace the template twice onto the envelope and cut out both pieces.
Paint a fish design on both pieces; one should be a mirror image of the other. Leave an unpainted border of at least an inch on the edge near the mouth.
Glue the two pieces together, right-sides out, along the two long seams; leave the tail and mouth seams open. Let the glue dry.
Cut an inch-wide ring from the top of the plastic cup and slip it into the fish's mouth. Fold the top inch of the Tyvek over the ring and glue it in place. Use clothespins to clamp the Tyvek in place as the glue dries.
Double-thread an embroidery needle with about five feet of string. Poke the needle through one side of the mouth, across the inside, and out the other side. Cut the needle free and knot the two ends of the string for the hanging loop. Wrap or tie the string to a dowel or a flagpole, and let it swim in the breeze.