Because the conventional pointe shoe is rigid when new, the dancer must break it in. This may involve any or all of the following: manually flexing the shoe back and forth, jumping on it, slamming it in a door, bashing it with a hammer, soaking it in warm water or alcohol, and scraping the sole. Finally, the shoe is often brushed with floor wax or shell, or reinforced with extra glue to give it a few extra minutes of life. All dancers sew on their own ribbons, which crisscross the ankles, keeping the shoe on and upright in the full-pointe position. Many use elastics as well. The breaking-in process can consume up to several hours of a dancer's time. Once broken in, the shoe quickly deteriorates. The conventionally-made, old-style pointe shoe often has a life span of only one performance. During the performance of a full-length ballet a ballerina will often replace her shoes at least once. The box becomes too soft to brace the toes adequately or the shank loses its stiffness. Sometimes old shoes can be re-used for class or light rehearsal, occasionally they are autographed and sold as souvenirs, but most are just thrown away. …