Fig. 1: Atomic stencilling generates a library of patch patterns on NPs.

a, Demonstrating stencilling using a Mona Lisa mask on a curved surface of pottery, which is subsequently painted with ink to create the silhouette. Mona Lisa pattern artwork adapted from ‘Mona Lisa Stencil’ by Vincent Robleto, used with permission. Scale bar, 20 cm. b, Schematics of stencilling on faceted NP surfaces using iodide to create the mask and 2-NAT-mediated PS-b-PAA grafting as paint. Scale bar, 30 nm. c, Library of different patchy NPs created by atomic stencilling of five different NP shapes. The particle shape schematics also highlight the existence of truncations (not drawn to scale). Within each NP shape of ‘w/ iodide’, top to bottom corresponds to increasing [I⁻]/[2-NAT]. Shown for each shape are representative transmission electron microscopy (TEM) or scanning electron microscopy (SEM) images (left) and predictions based on polymer scaling theory (right). For cuboctahedra and cubes, two patch patterns are shown with two different viewing angles. See more examples in Supplementary Figs. 3–15 and synthesis conditions in Supplementary Tables 1, 2 and 4–8. In experimental images, the polymer patches are false-coloured in cyan. The labels ‘w/ iodide’ (purple-shaded region) and ‘w/o iodide’ (unshaded region) refer to polymer-grafted NPs with and without iodide incubation, respectively. Scale bars, 20 nm.