Fulling board
A fulling board, called tovebrett in Norwegian, is a grooved wooden board used to felt small woollen garments. Wet fabric is worked against the board, commonly with soap. The treatment causes wool fibres to interlock and makes the textile denser. Its main purpose is material finishing rather than cleaning.
These boards resemble washboards but are generally described as narrower. Function is more useful than a fixed measurement: a washboard is associated with laundering, while a fulling board works the wool itself. Not every old grooved board can be securely identified from a photograph alone.
Collectors should preserve information about former use, place of origin and associated textiles. Compare that evidence with construction and wear. Grooves and rounded edges are not reliable dating evidence on their own. Record splits, missing wood and replaced parts. Where the original function remains uncertain, retain that uncertainty rather than turning a tentative identification into a definite one.
Sources: Ingun Grimstad Klepp, Store norske leksikon: tovebrett; Barbro Tronhuus Storlien, Store norske leksikon: toving.