Abstract: A shutter blade comprising a center portion having a receiving and a hooking end. The receiving end has a first opening which connects with a hooking end of another shutter blade. The first opening surface fits into and conforms with the first opening and there is continuous contact therebetween when the hooking end of the other shutter blade and the first opening surface are in a folded state. Alternatively, whether the first opening surface is of opposite shape as the hooking end surface or not, the receiving end can have a second opening separated from the first opening by a common wall. The shutter blade contacts a track mechanism through the second opening. Such shutter blades can be used in a shutter blade assembly in which a plurality of shutter blades are foldably connected in series and movably connected to the track mechanism.