Why can the rainbow only be stacked together in one direction?

Our organically designed Rainbow is hand-sawn from one single piece of wood which requires a lot of experience to do this work free hand. This leads to an asymmetrical construction, resulting in a more pleasant, natural appeal in comparison to using precise, symmetric stencils. Therefore, individual arcs may need to be rotated to obtain a perfect fit! It is exactly what makes our toy so special and each one unique.