Topas® Cyclo-Olefinic Copolymers (COC) developed by Ticona, Germany, are an entirely new class of amorphous, thermoplastic materials. Their unique property combination leads to a wide range of applications in pharmaceutical & medical packaging, capacitor films, food packaging films, optical parts/lenses, diagnostics and electrophotographic printing. As a toner binder resin Topas COC offers significant advantages over existing products especially when high process speed or improved image quality is required. The unique combination of excellent optical, thermal, rheological, mechanical, electrical and ecologically-friendly properties and its benefits to toner performance are described in the following article. Due to the flexible continuous production process the glass transition temperature, molecular weight and molecular weight distribution can be tailored independently according to the requirements of our customers. The introduction of Topas in commercial scale from the year 2000 on marks the beginning of a new era of high performance printing.