controlled except by external means. Ml Koh-I-Noor.0mm leadholders and colour leads. Many of these have a locking mechanism one way to allow the lead to be pushed back into the pencil. Other designs use a precisely-fitted metal sleeve to guide and support the lead, and do not need a rubber retainer. 4 (October 1985. Pigments edit Mechanical pencils with colored leads are less common, but do exist. Archived September 19, 2009, at the Wayback Machine.
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The first spring -loaded mechanical pencil was patented in 1877 and the Community of Manzanar a twist-feed mechanism was developed in 1895. Koh-i-Noor makes mechanical colored pencils with replaceable leads.0,.15 and.6 mm sizes. 15 See also edit Notes and references edit mechanical pencil definition. Henry Petroski, The Pencil :A History of Design and Circumstances, Random House, 2011 Random House, National Geographic Magazine, Vol. Mark Hill Collects: The 20th Century Design and Collectibles Blog.