The Master runecrafter hat is a part of the Master runecrafter robes outfit and can be bought from Wizard Elriss in the Runecrafting Guild for 15,000 Runecrafting guild tokens or from Stanley Limelight for 500 thaler. When worn alone, it provides the wearer with a +1% boost to experience when Runecrafting. However, when the full master runecrafting robes outfit is worn, this boost is increased to +5%. The experience boost will stack with other Runecrafting experience boosts, such as when using Runecrafting gloves or when crafting runes in The Great Orb Project, but has a limit of 700 xp per action.
It does not allow the goggles to be worn on the wearer's eyes, unlike the runecrafter hat.