A package includes a bag in a sleeve. The sleeve includes biconcave panels that are opposite from one another and each have opposite concave edges, and biconvex panels that are opposite from one another and each have opposite convex edges. The concave and convex edges are respectively foldably connected to one another by arcuate fold lines. When the sleeve is erected, each of the biconvex panels may be in a concave configuration with respect to the interior of the sleeve.