Although they've manufactured ball-point pens for decades, no Chinese firm has yet mastered the production of the small metal balls essential to the pens' function. They have tried for years, but are only in 2018 making progress in finding a material of suitable hardness, shape-ability, and cost for their pens. It seems, sometimes the little things really are the most difficult!

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washingtonpost.com/finally-china-manufactures-a-ballpoint-pen-all-by-itself