When you shine a light at a 3D object, the way the shadows hit its features is part of how our brain interprets its shape — and it's something that a 2D print pretty convincingly can't do. That is, until now. A group of researchers from HP, UC Santa Cruz, and 3M have created a type of paper that can be used to interact with light the way that real, 3D objects do.
Dubbed reflectance printing, the paper is covered with a lattice of tiny divots, each of which can be printed in different ways, using a family of techniques known as specular microgeometry. These small indentations are printed to match the way that pixel of the photograph would reflect light if it were the original 3D object. As you shine and move a light around it, the pixels accurately change into shadow like they would on a real object.
At this stage, the pixels themselves are pretty big and the resolution is pretty mediocre — but the foundation is definitely there. Who knows, in a couple of years your next Crate & Barrel catalog could give you a much better idea of how that vase would really look.