{
  "name": "V-fold and parallel fold: opening path in a rigid-sheet model",
  "desc": "Opening path of two v-fold pieces and one parallel fold in a rigid-sheet model with no paper thickness, from 0 to 180 degrees and back in 2 degree steps (plus 0.5 and 1 degree near closing): height of each piece above the left page, smallest gap to another sheet (for a v-fold piece and its facing page, the 5 mm next to the spine corner are left out, since all the sheets meet there), whether any sheet passes through another, whether the piece stays inside the page, and the rigidity error. Computed with paper-mech 1.0.0, 2026-11-14, and re-issued with paper-mech 1.1.0, 2026-11-15 (values unchanged); model numbers, not measurements of real card. The qualifier on each v-fold row states and defines the 5 mm rule: the piece's corner at the spine vertex is cut off between the points 5 mm from the vertex on its two edges.",
  "lic": "CC BY 4.0",
  "lic_url": "https://creativecommons.org/licenses/by/4.0/",
  "by": "Fold, Knot & Bind",
  "url": "https://foldknotbind.com/paper-mechanisms/v-fold-pop-up/",
  "from": [
    "Paper-mechanism model by Fold, Knot & Bind (paper-mech 1.1.0): v-fold pieces A (alpha 45, beta 80) and B (alpha 25, beta 40), parallel fold with panels 45 mm and 30 mm; pages 140 by 200 mm; 2026-11-15 (values unchanged from paper-mech 1.0.0, 2026-11-14)"
  ],
  "how": "Compiled by Fold, Knot & Bind from the data listed"
}