Patterning via self-organization and self-folding. Pattern formation by self-organization and self-folding provides unique opportunities for the materials community by addressing many of the issues associated with conventional lithography. The articles in this issue of MRS Bulletin focus on various methods of patterning using self-organization and self-folding. Most of these methods seek to control and pattern diverse materials across a range of length scales at low cost in a way that gives rise to new functionalities. The cover shows one example of how capillary forces can deform vertical carbon nanotubes (CNTs) to create an arrangement of circular patterns on a sub-millimeter scale, with the same complexity of real crop circles spanning 100 meters or more in diameter. When covered by a liquid droplet, some of the straight CNTs remain vertical, while others self-fold onto the substrate as dictated by their initial geometry, demonstrating the control that can be achieved by elasto-capillary engineering. Image courtesy of S. Tawfick and A. John Hart. See the technical theme that begins on page 93.