Coloured cryo-scanning electron microscopy image of an anterior lateral spinneret of a web-building spider (Uloborus plumipes) snap frozen during the spinning of a silk anchorage. The array of nozzles of the piriform glands (spigots, yellow) simultaneously extrudes glue coated silk (white) that is applied onto the substrate by specific movement patterns of the spinneret (green). Adjacent hairs (setae, brown) probably serve as chemosensors to assess the substrate surface and as brushes to remove dust particles at the attachment site. Image by Ingo Grawe (Functional Morphology and Biomechanics, University of Kiel) and Jonas Wolff (Macquarie University, Sydney). See ‘Three-dimensional printing spiders: back-and-forth glue application yields silk anchorages with high pull-off resistance under varying loading situations.’ J. R. Soc. Interface14: 20160783. http://dx.doi.org/10.1098/rsif.2016.0783.