after the introduction of the maintenance-free, mass-produced steel dip nib by John Mitchell, knives were still manufactured but became known as desk knives, stationery knives or latterly as the name stuck "pen" knives. There is a small but significant difference between a pen knife and a quill knife, in that the quill knife has a blade that is flat on one side and convex on the other which facilitates the round cuts required to shape a quill. A "pen" knife by contrast has two flat sides. This distinction is not recognised by modern traders, dealers or collectors, who define a quill knife as any small knife with a fixed or hinged blade, including such items as ornamental fruit knives. Today While quills are rarely used as writing instruments in the modern day, they are still being produced as specialty items, mostly for hobbyists. Such quills tend to have metal nibs or are sometimes even outfitted with a ballpoint pen inside to remove the need for a separate source of ink. According to the Supreme Court Historical Society, 20 goose-quill pens, neatly crossed, are placed at the four counsel tables each day the U.S. Supreme Court is in session; "most lawyers appear before the Court only once, and gladly take the quills home as souvenirs." This has been done since the earliest sessions of the Court. In the Jewish tradition quill pens, called kulmus (), are used by scribes to write Torah Scrolls, Mezuzot, and Tefillin. Music Plectra for psalteries and lutes can be cut similarly to writing pens. The rachis, the portion of the stem between the barbs, not the calamus, of the primary flight feathers of birds of the Corvidae was preferred for harpsichords. In modern instruments, plastic is more common, but they are often still called "quills". The lesiba uses a quill attached to a string to produce sound. See also The spiny barbs of a porcupine In a zoological context, a spine is a hard, needlelike anatomical structure. References External links A brief history of writing instruments Tutorial on Medieval method of creating quills Feathers Writing implements Poultry products