To access the data, click or select the words “Appendix 2.” A tilt series was acquired by tilting the specimen around a single tilt axis, in two degree increments over a limited tilt range (+60°, - 60°). See Appendix 3 to view the entire tilt series. The image stack has been contrast-inverted and therefore the proteins are shown in white whereas the background is shown in black. The red arrowheads highlight the double dark transverse bands, formed by N- and C- globular domains of type VI collagen. This feature of collagen VI is not clearly seen in two-dimensional projections. The collagenous triple-helices (yellow arrowheads) run nearly perpendicular to the dark bands.