Self-Correcting Ink

• Type: Magical Item (Magical Writing Supply)
• Owners: Various students at Hogwarts School of Witchcraft and Wizardry and other witches and wizards.
• Maker: Unknown

Self-Correcting Ink is a magical type of ink sold for use with a quill. While its specific physical appearance is not described, it is presumably sold in bottles, similar to standard non-magical ink, and is available for purchase at places like Diagon Alley. Its defining feature is not its appearance but its enchanted properties.

The primary function of Self-Correcting Ink is to automatically detect and correct spelling errors as the user writes. The enchantment is sophisticated enough to recognize context and specialized terminology within the magical world.

• Error Correction: The ink can identify and fix mistakes in both mundane and magical vocabulary. For example, it would have been able to correct an incorrectly written incantation or charm name in a Charms essay.
• Academic Use: It is a legitimate tool for general academic work, such as homework essays. Hermione Granger considered its potential usefulness on her own work, implying it is a common and accepted study aid.
• Examination Ban: The use of Self-Correcting Ink is strictly forbidden during formal examinations at Hogwarts, such as the Ordinary Wizarding Levels (O.W.L.s). Using it under exam conditions is considered a form of cheating. This rule is enforced to ensure that a student's own knowledge and accuracy are being tested. This places it in a similar category to the Self-Spelling Quill.

The origins and inventor of Self-Correcting Ink are not known. It was an established and available product within the wizarding world by the 1990s, commonly known to Hogwarts students.

Self-Correcting Ink is mentioned in Harry Potter and the Order of the Phoenix following the Charms O.W.L. exam. An distraught Hermione Granger laments that she made a spelling mistake on her written paper, writing “lunare” instead of the correct “lunette”. She wishes she had been allowed to use Self-Correcting Ink, stating that it would have caught and fixed the error for her. Ron Weasley sharply reminds her that the ink was banned from the exam, highlighting the strict rules surrounding the O.W.L.s. This interaction underscores Hermione's academic perfectionism and anxiety, while also providing a small but clear example of the regulations that prevent cheating in wizarding education.

This item is mentioned only in the novels and does not appear in the film adaptations. There is no further information regarding its creation or properties from J.K. Rowling's interviews or supplementary writings on Pottermore/Wizarding World.