Fountain pen. Shaft: Made entirely of stainless steel or interwoven with gold threads. All other metal parts feature high-quality silver plating and a palladium finish. Materials: Rhodanized 18-carat gold nib. Available in F, M, and B nib widths.The TecFlex line from Porsche Design employs a stainless steel mesh borrowed from the racing world. The extraordinary flexibility of this material perfectly suits the nature of the products.