There are yarns commonly known as raised or matted yarns currently available on the market, obtained by very laborious manufacturing processes involving a plurality of stages through the various operating machines, and in short obtained by an operation of extraction of the fibers (raising) from the processed yarn, involving hard treatment of the material, which beforehand has to undergo the traditional spinning. Moreover, the yarns thus obtained, by virtue of the very characteristics of the operating machines, have a uniform configuration, in the sense that their external characteristics are kept constant.