His collections are characterized by the smooth and understated, often in natural fabrics such as mohair, wool, and suede, in subtle colours. He set up his own business 1968, specializing in designing coats and suits, and expanded into sportswear in the mid-1970s. His designer jeans became a status symbol during the same period. In Aug 1995 Klein withdrew an advertising campaign for designer jeans following allegations that it violated child pornography laws; in Nov it was announced that he would not face prosecution as the models used were not minors.