{
  "title": "The 17 wallpaper groups: symmetry facts, this page’s patterns and confirmed historical examples",
  "description": "One row per wallpaper group: the lattice column gives the repeat-cell shape of this page’s own drawing of that group (not a rule for every pattern of the group), followed by turn orders, mirrors, glide lines off the mirrors, and the confirmed historical example from the 1910 printing of The Grammar of Ornament, where there is one.",
  "license": "CC BY 4.0",
  "license_url": "https://creativecommons.org/licenses/by/4.0/",
  "creator": "Drawn Mathematics",
  "page": "https://drawnmathematics.com/symmetry/wallpaper-groups/",
  "derived_from": [
    "Symmetry facts: exact computation on the 17 patterns of this page (one F repeated by each group’s moves)",
    "Examples: this site’s classification of crops from the Polona scan of Owen Jones, The Grammar of Ornament (London: Bernard Quaritch, 1910), confirmed by an independent blind check"
  ],
  "method": "Compiled by Drawn Mathematics from the data listed",
  "data_credit": [
    "Computed for this page from 17 generated patterns, each checked by exact computation",
    "Historical examples: Owen Jones, The Grammar of Ornament (London: Bernard Quaritch, 1910), Polona scan, National Library, Warsaw (accession 1.028.021), public domain; group names are this site’s classification"
  ]
}