Three-inch magnetic rollers deliver volume and body to long, straight hair. This photo of Elizabeth Hurley is from www.shampooandset.com.
This picture of the back of a roller set client is from www.shampooandset.com It gives you an ideal of roller placement and the use of a net to hold the rollers in place. Also, look closer at the anchoring of the rollers. Can you see that two roller pins are used to hold the rollers in place? More than likely, the hair on the rollers are rolled as a flip set in order to keep the roots flat. Please see my separate article on flip roller sets. My salon has a large inventory of 3-inch rollers for long hair services.