Karl Ludwig Nessler (2 May 1872 in Todtnau, Germany – 22 January 1951 in Harrington Park, New Jersey, USA) was the inventor of the permanent wave.
Karl Nessler was the son of a shoemaker from Todtnau, a small town located high in the Black Forest, just beneath the Feldberg. He got the idea for the perm early in his youth. He began an apprenticeship which he dropped. He worked in Basle and Milan in different jobs, learned Italian and French and finally moved to Geneva; there he worked again as a barber and hairdresser and finished his apprenticeship. Adapting to the French-speaking environment, he called himself Charles Nessler, and often spelt it "Nestle". Later, he moved to Paris, where he tested his first perm on a certain Katharina Laible from Ulm.
In 1902, another invention, artificial eyebrows, was patented in the United Kingdom. He moved to London and married Katharina Laible. His attempts to convince his English colleagues to use his invention failed, but his electric permanent wave machine was patented in London in 1909.,. In 1912, some improvements of his apparatus were patented again. In 1914, he patented a last improvement before the outbreak of the war.
When World War I broke out, he was interned and his assets confiscated as alien property. In 1915, he fled to the United States where he learned that counterfeited copies of his invention were already being sold. In April 1919, his improved Hair Curler was filed at the United States Patent and Trademark Office. He was already an American citizen. The holder of the patent was his Nestle Patent Holding Co. Inc. He developed a do-it-yourself kit for perms and opened a chain of hair salons. In 1927, his chain had 500 employees, with branches in New York City, Chicago, Detroit, Palm Beach and Philadelphia. The annual advertising budget was $300.000.