Quill (or quill pen) is a writing tool which is made from a flight feather of a large bird and which uses ink to leave marks on a writing surface. The point of the feather is treated so it can be used for writing and a hollow shaft of the feather holds the ink which, from there, flows to the tip by capillary action. Quills were made from feathers of different birds, but the best ones were made from goose, swan, and turkey feathers.
Before quills, people used styluses to write on clay and wax and reed pens with ink to write on papyrus and animal skins. The problem with clay texts was that they were heavy and brittle and difficult to write (clay tablets had to be baked when finished), wax tablets didn’t last long and were sensitive to heat, and reed pens were too stiff and didn’t last long because they would wear out fast. That is why they were spontaneously replaced with quills (but not completely).
It is not known when the first quills appeared, but it is known that some parts of the Dead Sea Scrolls were written with quill in 2nd century BC. St. Isidore of Seville mentions them in the 7th century in his writings, and it is believed that quills then began to spread as a popular method of writing as better than reed pens. With quills, it was easy to write on parchment and vellum. They were also used with fine brushes to illustrate manuscripts with figures, decorations, and images and become more and more popular from the 15th century on, when writing and flourished writing started to spread through the western world. Many important documents were written and signed with quills like Magna Carta and American Declaration of Independence. The popularity of quills lasted until metal pens entered mass production in the 19th century but they are still used today in some cases. For instance: 20 goose-quill pens are placed at the tables each day the U.S. Supreme Court is in session.
But you can’t just take a feather, dip it in ink and use it for writing - you have to prepare it (well, technically you can, but it won’t work that good nor write that beautiful). There are different methods of treating feathers to become quills. They all use large feathers (only 5 or 6 largest) from goose, swan or turkey (although feathers of crow, eagle, owl or hawk can also be used) and try to harden its shaft. Some methods place shaft of the feather into hot ashes until it is soft. After that, father is flattened on a hard surface with a pen knife and rounded with fingers. Other methods use hot water or hot sand, but the main idea is to cure the feather and make it more flexible so it can withstand longer writing. After the curing, next step is removing of the point of the feather with a small knife (called pen knife). The point is removed under the angle, not far from the point and an upper side of the quill. It makes an oval hole. Then, a slit is made on the top side of the quill with the same pen knife. Slit will lead the ink from the shaft to the point of the quill by capillary action. On the lower side of the quill, a scoop is then cut which is larger than a first cut. Tip of the quill is slowly taking shape. Corners on the both sides of the nib are cut off, and nib is then made flat. If made correctly, quill can last long without the need to be sharpened again.