In ancient Rome, scribes wrote on papyrus (an early form of paper) with a thin metal rod called a stylus, which left a light but readable mark. Other early styluses were made of lead. Today, we still call the core of a pencil the “lead” even though it is made from non-toxic graphite. Writing cores are a mixture of graphite and clay. By varying the ratio of graphite to clay, pencil makers can adjust the “hardness” of the writing core. Therefore, consistency of graphite quality, in terms of crystallite structure, lubrication and ash composition is a key factor. These targets can only be achieved by very well defined, high performance raw materials of outstanding consistency such as TIMREX® graphite powders.
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