Pencil Drawing Female Portrait

On 30 March 1858, Hymen Lipman received the first patent for attaching an eraser to the end of a pencil. In 1862 Lipman sold his patent to Joseph Reckendorfer for $100,000, who went to sue the pencil manufacturer Faber-Castell for infringement. In 1875, the Supreme Court of the United States ruled against Reckendorfer declaring the patent invalid.
Manufacture
Modern pencils are made industrially by mixing finely ground graphite and clay powders, adding water, forming long spaghetti-like strings, and firing them in a kiln. The resulting strings are dipped in oil or molten wax, which seeps into the tiny holes of the material, resulting in smoother writing. A juniper or incense-cedar plank with several long parallel grooves is cut to fashion a “slat,” and the graphite/clay strings are inserted into the grooves. Another grooved plank is glued on top, and the whole assembly is then cut into individual pencils, which are then varnished or painted. Afterwards people can then add personal things like pencil grips and eraser toppers. Eraser toppers are extra erasers that can be removed after being used.