This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
crossingsymmetrical.svg Eightcrossing knot with fourfold symmetry or Carrick mat Converted from the following vector PostScript source code translate setrgbcolor setlinewidth sqrt div def arc neg arc neg arc arc closepath gsave setlinewidth setgray stroke grestore stroke gsave setlinewidth setgray neg arcn