(a) Liquid VPS-22 (see Methods) is poured onto a sphere (R=38 mm), then drains under gravity and eventually cures to produce an elastic shell (see Supplementary Movie 1). The time interval between each frame is 2 s. (b) Similar procedure to that of (a) for spheres in a range of radii, 1≤R[mm]≤375. (c) Thickness of the elastic shells, hf, as a function of , for various polymer solutions (VPS and PDMS) and temperatures (for PDMS). See Methods for details. The solid line corresponds to equation (1). Inset: An elastic shell is cut along a meridian for the thickness measurements. Scale bars, 10 mm.