"The wires run vertically and are bent into a zig-zag pattern so that each "zig" hooks with the wire immediately on one side and each "zag" with the wire immediately on the other. This forms the characteristic diamond pattern seen in this type of fence."

https://en.wikipedia.org/wiki/Chain-link_fencing

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Note added at 1 hr (2020-03-08 18:33:46 GMT)
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Typo apropos the entry: "chain-link"

Same link as above:
"An improved version of the weaving machine winds two wires around the blade at once to create a double helix. One of the spirals is woven through the last spiral that is already part of the fence."

Images of Baumkuchenwicklung mesh here:
https://www.reidl.de/4eck-baumkuchenwicklung-60x2-8x1250-a-2...

UK chain-link image here:
https://www.wickes.co.uk/Wickes-Chain-Link-Wire-Fencing---90...



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Note added at 1 hr (2020-03-08 18:45:03 GMT)
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And here another image showing the different shapes of mesh rolls (German source):
https://books.google.de/books?id=eY9DBbx4uXIC&pg=PA11&lpg=PA...