It's made in cotton, it's easy to apply on hair, and have good curling result.You can even apply when sleep, as it is soft, and would not damage your hair. Method 1 1. When hair is about 80 to 90% dry after washing 2. Curl with the sponge curlers and go to sleep 3. Wake up with natural looking curls the next day Method 2 1. Spray little water and curl hair with sponge curlers 2. Blow dry with hair dryer on low heat for about 15 to 20 minutes 3. Remove sponge curlers after