hairdresser Marcel Grateau introduced heated metal hair care implements such as hot combs to straighten hair. Madame C.J. Walker used combs with wider teeth and popularized their use together with her system of chemical scalp preparation and straightening lotions. Her mentor Annie Malone is sometimes said to have patented the hot comb. Heated metal implements slide more easily through the hair, reducing damage and dryness. Women in the 1960s sometimes used clothing irons to straighten their hair. In 1909, Isaac K. Shero patented the first hair straightener composed of two flat irons that are heated and pressed together. Ceramic and electrical straighteners were introduced later, allowing adjustment of heat settings and straightener size. A ceramic hair straightener brush was patented in 2013. Sharon Rabi released the first straightening brush in 2015 under the DAFNI brand name. The ceramic straightening brush has a larger surface area than a traditional flat iron. Crimping irons Crimping irons or crimpers work by crimping hair in sawtooth style. The look is similar to the crimps left after taking out small braids. Crimping irons come in different sizes with different sized ridges on the paddles. Larger ridges produce larger crimps in the hair and smaller ridges produce smaller crimps. Crimped hair was very popular in the 1980s and 1990s. See also Hot comb Hair dryer Hair roller References Hairdressing Home appliances