Core-yarns in general represent combinations of filaments and staple fibers of various materials. In recent years, Zwickauer Kammgarn GmbH re-interpreted core-yarns and developed new technologies. Triwitex® is already accepted on the market. It turns the idea of a classic core-yarn upside down. The filament is not in the middle of the yarn but wrapped around the outside. This leads to a much better abrasion resistance up to 250.000 Martindale-cycles and Pilling grade 5 without losing the characteristic touch of a staple fiber yarn. Sleewitex® is on its way to the market. Where the filament in a conventional core-yarn lies partially on the outside of the yarn, the filament in Sleewitex® is completely straight due to adjustments of the drafting system. This results in enhanced adjustability and controllability of optical and clothing physiological characteristics. For example, the unpleasant touch of high modulus polyamid filaments or the look of non-dyable flame-retardant filaments can be fully covered by staple fibers.