An Teak magic wardrobe flatpack can be made at a workbench (Steel framed bench or better) in the workshop of a player-owned house. Like when making the normal Teak magic wardrobe, this requires 60 Construction, uses 4 teak planks and gives 360 experience. The flatpack can then be used on a magic wardrobe hotspot in a Costume room, either in building mode or not. This requires no Construction level and gives no experience.
The cost of making and selling a Teak magic wardrobe flatpack from scratch gives a profit of: -3,060
After completing the hard Fremennik Tasks, they can also be traded to Advisor Ghrim in exchange for 225 coins being added to your kingdom's coffers in Miscellania. See Flatpack: Miscellania reselling for details.
See Magic wardrobe for a list of armours that can be stored.