A teak dining bench flatpack can be made at a workbench (Oak workbench or better) in the Workshop of a Player-owned house. This requires 38 Construction, uses 4 teak planks, and gives 360 experience. The flatpack can then be used on a seating space hotspot in the Dining room, while in building mode. This requires no Construction level and gives no experience.
The cost of making and selling a teak dining bench flatpack from scratch gives a profit of: -3,137
After completing the hard Fremennik Tasks, hey 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.