The Cotton Cap is a mystic headgear in Final Fantasy XII that boosts the wearer's Magick Resist by 4 and Magick Power by 2. In the Zodiac versions, it also gives 5 to MP. It is the weakest mystic hat in the game and basic equipment.
The Cotton Cap is sold for 100 gil in Rabanastre and Nalbina Fortress, and is initially equipped on Penelo. It is found as a treasure in Dalmasca Westersand's Galtea Downs (60% chance to appear, 45% chance for gil, 50% chance the item treasure is the Cotton Cap without the Diamond Armlet equipped). It still rarely drops from the Alpha Hyena and from the Hyena in Giza during the dry.
The Cotton Cap is the weakest mystic hat, giving minimal Magick Resist and 2 Magick Power, as well as 5 MP in the Zodiac versions. It falls off in usefulness fast. Mystic armor offer magick-related bonuses that affect all types of magickal actions, from casting black magick to damage an enemy, to casting white magick to heal the party. Magick Power is also a factor when determining damage dealt by katana, staves, and maces.
In the Zodiac versions, White Mage, Red Battlemage, Black Mage, and Bushi can equip it, and Penelo starts with the license for it so she can wear it no matter the job, and joins the party with it already equipped. If the player starts Vaan in any of the aforementioned jobs, the player can already buy the superior Magick Curch from the shops, and so there is no need to purchase the Cotton Cap. In the original version, the player can still hold off buying the Cotton Cap, and go buy the superior Magick Curch when Penelo leaves the party, however, in this version Vaan can wear any equipment piece and the HP-boosting light armor and Strength-boosting heavy armor are likely better suited in this early point.