Quill

A quill is a writing instrument made from a feather whose tip has been cut into a pointed shape. It is the standard writing instrument in the Wizarding world, as opposed to pens and pencils in the Muggle world. They usually have to be dipped into ink. There is a great variety of quills, some plain and simple, some (like Fwooper quills), more fancy-looking, others enhanced with magical properties.

Numerous types of feathers are used including Pheasant, Eagle, Peacock (Gilderoy Lockhart's favourite), and perhaps Phoenix. Augurey feathers, however, are no good for this purpose as they repel ink.

In 1994, Harry Potter used an eagle feather quill to write a letter to Sirius Black. In 1995, while at the Ministry of Magic for his hearing, he noticed an Auror dictating a report to his quill. Scrivenshaft's Quill Shop sells pheasant-feather quills. Hermione bought a black-and-gold one during the first Hogsmeade visit of the 1995–1996 school year. Albus Dumbledore had a "handsome scarlet quill" on the desk in his office; since it matched the colour of Fawkes' body feathers, it might have been a phoenix-feather quill.

Anti-Cheating Quills

 * Used at Hogwarts during written exams. They are charmed with an Anti-Cheating spell, making it impossible to cheat.

Auto-Answer Quills

 * They are banned during written exams at Hogwarts School. They probably write their own answers.

Dolores Umbridge's Blood Quill

 * This quill does not use ink, but uses the writer's own blood to mark the paper. Harry had to use this quill to write lines in 1995 while serving detentions with Professor Umbridge. His hand is now permanently scarred with I must not tell lies from writing with this quill. Lee Jordan also was forced to use this quill for joking about a rule Professor Umbridge imposed.

Magical Quill

 * Detects the birth of each wizard or witch, then writes his or her name down in a large parchment book at Hogwarts. The Deputy Head checks the book every year, and then sends owls to these children as they approach their eleventh birthdays to invite them to attend Hogwarts.

Quick-Quotes Quill

 * Great for reporters, this quill writes what the speaker dictates - often exaggerating the story. Rita Skeeter has an acid green one.

Self-Inking Quills

 * These quills are sold at Weasleys' Wizard Wheezes, these quills probably ink themselves without needing to be manually dipped in an inkwell.

Sugar Quills

 * A confection that looks like a writing quill, so that it can be nibbled on discreetly during classes. This treat is Quill-lrg.png.]]sold at Honeydukes Sweetshop.

Smart-Answer Quills

 * These quills write smart-aleky answers and are sold at Weasleys' Wizard Wheezes.

Spell-Checking Quills

 * Corrects the user's spelling, sold at Weasleys' Wizard Wheezes. Ron Weasley had one, but its charm wore off leaving his homework terribly misspelt (example: his name was written as Roonil Wazlib.)

Self-Spelling Quills

 * Presumably similar to the above and a banned deviced in examinations.

Appearences

 * Harry Potter and the Chamber of Secrets (book)
 * Harry Potter and the Order of the Phoenix (book) 
 * Harry Potter and the Chamber of Secrets (film)
 * Harry Potter and the Order of the Phoenix (film) 
 * Pottermore