Ballpoint Pen

A ballpoint pen (Philippine English: ballpen, British English: biro) is a writing instrument, with an internal ink reservoir and a sphere for a point. The internal chamber is filled with a viscous ink that is dispensed at its tip during use by the rolling action of a small sphere. The sphere, usually from 0.5 mm to 1.2 mm in diameter, may be made of brass, steel, tungsten carbide, or any durable, hard (nondeformable) material.

Read more about Ballpoint Pen:  History, Description, As Art Medium, Standards

Famous quotes containing the word pen:

    “Every drop of ink in my pen ran cold.”
    —Horace Walpole (1717–1797)