A Gilded magic wardrobe flatpack can be made at a workbench (Bench with lathe only) in the workshop of a player-owned house.
Like when making the normal Gilded magic wardrobe, this requires 87 Construction, uses 4 mahogany planks, 1 gold leaf and gives 860 experience. The flatpack can then be used on a magic wardrobe hotspot in a Costume room.