An oak dresser flatpack can be made at a workbench (Oak workbench or better) in the workshop of a player-owned house. Like when making the normal Oak dresser, this requires 37 Construction, uses 2 oak planks, 1 molten glass, and gives 121 experience. The flatpack can then be used on a dresser hotspot in a Bedroom, either in building mode or not. This requires no Construction level and gives no experience.
The cost of making and selling an oak dresser flatpack from scratch gives a profit of: -999
After completing the hard Fremennik achievements, they can also be traded to Advisor Ghrim in exchange for 56 coins being added to your kingdom's coffers in Miscellania. See Flatpack: Miscellania reselling for details.