That depends a lot on whether you choose four individual prints that can be hung individually or as a set, or a quad. A quad is a canvas print where the original artwork is spread across four prints for effect. On the Zazzle print platform, the material is a stretched canvas. Because it is a print that is split for effect, it usually looks best when hung in a rectangular grid. The custom art prints, on the other hand, offer a wider range of materials. These include posters, photo prints, faux or stretched canvas, or acrylic wood or metal. Your choice depends on print effect, quality, and affordability. Most importantly, how you choose to hang them is up to you and the space you have available. Ideas include as a double pair, stacked on top of each other, side-by-side in a straight line, in an upside-down line, or in a paralleogram arrangement.