Kerf: a laser removes a line of material, so pieces cut from one shared line are loose by that much. One shared line cannot be moved to make both sides bigger, so instead each knob is made to lock: its neck is pinched and its head swollen by the kerf, so it cannot slide out of its socket. Set it to your laser's cut width (0.1 to 0.2 mm is usual). Smallest piece: any piece smaller than this joins the neighbour it shares the most edge with, so there are no slivers. This matters most on a road-cut puzzle, where two roads close together would otherwise make strips nobody can pick up.
Oct 23, 2026