Madame C.J. Walker used combs with wider teeth and popularized their use together with her system of chemical scalp preparation and straightening lotions .
In the 1870s , the French 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 combs ' use together with her system of chemical scalp preparation and straightening lotions .
In the 1870s , the French hairdresser Marcel Grateau introduced heated metal hair care implements such as hot combs to straighten hair .