Analysis of orb webs of the garden cross spider (Araneus diadematus) showed that these vertical webs have a significant up/down asymmetry. Experiments demonstrated that the spider runs down faster than up, and thus confers a relatively higher foraging value to sections below the hub. Simulations suggested that the density of capture spiral spacing, prey size, and the density of prey should all affect the capture efficiency of a web. Webs lose effective capture area because of overlap of the capture zone around each thread; the smaller the prey, the finer the mesh can be without losing effective area. Lower sectors of the web have a particular mesh size (height and length of capture spiral segments) throughout, whereas in the upper sectors the mesh size changes, widening from the hub towards the periphery.