Multi-planarizable quivers, orientifolds, and conformal dualities

We study orientifold projections of families of four-dimensional $\mathcal{N}=1$ toric quiver gauge theories. We restrict to quivers that have the unusual property of being associated with multiple periodic planar diagrams which give rise, in general, to inequivalent models. A suitable orientifold projection relates a subfamily of the latter by conformal duality. That is, there exist exactly marginal deformations that connect the projected models. The deformations take the form of a sign flip in some of the superpotential interactions, similarly to the $\beta$-deformation of $\mathcal{N}=4$ SYM. Our construction generalizes previous results on the orientifold projections of the PdP${}_{3b}$ and PdP${}_{3c}$ singularities.