Inflate and tie off the end of a party balloon. Tie a 24-inch piece of string to the end of the balloon. Tie the other end of the string to an eye hook or ceiling fan. Line the area below the balloon with trash bags or newspaper to protect your flooring. When choosing a balloon, select one in the size and shape you want the finished lampshade to be.
Empty the contents of a quart of wallpaper glue or paste into a bucket. Place a skein of cotton or acrylic string into the glue. Work the glue into the string while wearing rubber gloves.
Place the loose end of the skein of string against the balloon. Wrap the string around the balloon. Use a set pattern or random placement. Make sure the string overlaps as you go to give the shade structure. Cover the entire balloon, leaving a 2-inch hole at the top of the balloon to allow for the lamp fixture and light bulb. Tuck the loose end of the string under one of the overlapping pieces to keep it from unraveling.
Leave the balloon hanging overnight so the glue can dry. Cut the end of the balloon to deflate it. Remove the balloon from the string structure. If the inside of the string is still damp, let it dry another three to four hours.
Turn the string lampshade over and insert a light bulb and lamp fixture through the hole. Rest the fixture on the opening of the hole to support the shade.