The production of a 0.4mm ball point tip has been achieved using the 3-dimples supporting system technology. In this system, the 0.4mm carbide alloy ball is mounted by making three depressions in the tip of a fine stainless steel pipe, in contrast to the traditional system of hollowing out the metal tip. Since the ball will be supported on 'points' the reduction in wear surface allows smoother rotation. The resulting stroke width is just 0.2mm. These G-Tec C4 gel ink pens use a bio-polymer ink that prevents feathering or ink stains giving you smooth writing each time with beautiful, vivid colouring. The tungsten carbide ball used in the BLGC401pens makes these pens durable and reliable for use until the last drop of ink.