I have naturally straight, soft, and naturally blond hair that is strong and well-managed. It has never been chemically treated, like dyed or permanent. Washed twice per week, air dried only, never styled with heat, no sun damage, no hairspray. I take a vitamin with biotin and omega3 in it. I use shampoo and conditioner. After washing use balsam spray and hair oils (coconut, cactus). I eat healthy food and do not use alcohol, tobacco or any drugs. My hair is fresh and beautiful, 3,2 inches thick. I sell up to 15 inches of the hair length.