- For the flatpacked version, see Mahogany fancy dress box (flatpack).
The Mahogany fancy dress box (also known as Mahogany costume box or Mahogany cos box in the Grand Exchange and task system) is a piece of furniture that can be built in the Costume room of a player-owned house with the Construction skill. Costume boxes are used to store costumes or fancy dresses from random events.
The mahogany costume box is used to store all types of costumes. Building this costume box requires at least 80 Construction and 2 mahogany planks.
Costume boxes can be flatpacked, and bought from the Grand Exchange. Building a flatpacked costume box does not require the actual Construction level.