Biscornu

{{Short description|Ornamental pincushion}} {{refimprove|date=December 2009}} [[File:Thai biscornu with orchid cross-stitch decoration.jpg|thumb|A Thai-themed biscornu, stitched on 14-count white Aida.]] A '''biscornu''' is a small, octagonal, stuffed ornamental pincushion.<ref>{{Cite journal |last=Saluja |first=Kavita |date=2017 |title="The Rabbit Hole" – New Frameworks of Awareness for Fashion Pedagogy |url=https://thescopes.org/journal/art-and-design/art-and-design-15/the-rabbit-hole-new-frameworks-of-awareness-for-fashion-pedagogy |journal=Scope (Art & Design) |volume=15 |pages=120–127}}</ref> It is usually made using evenweave fabric, such as Aida cloth, cotton or linen.<ref name="Watts">{{cite book|last=Watts|first=Bobbie|title=Teach Yourself to Make Biscornu (Leisure Arts #5406)|url=https://books.google.com/books?id=U4N3CDORQZUC|accessdate=9 August 2014|date=January 2012|publisher=Leisure Arts|isbn=978-1-60900-122-3|page=1}}</ref> The technique involves joining two embroidered squares framed with a backstitch border with a whip stitch in such a way that each corner of one square is attached to the middle of the side of the other.<ref>{{cite web|url=http://www.nordicneedle.net/guides/how-to-make-biscornu/|title=Biscornu How To|work=Nordic Needle|accessdate=2017-11-30}}</ref><ref name=":0">{{Cite journal |last=Seaton |first=Katherine A. |date=2021-10-02 |title=Textile D-forms and D 4d |journal=Journal of Mathematics and the Arts |language=en |volume=15 |issue=3–4 |pages=207–217 |doi=10.1080/17513472.2021.1991134 |s2cid=232257692 |issn=1751-3472|doi-access=free |arxiv=2103.09649 }}</ref> The term comes from the French adjective ''biscornu'', which means irregular, skewed, or odd.<ref name=":1" /> thumb|alt=cross stitched biscornu with satin ribbons|Biscornu with satin ribbons on Lugana

Biscornus are relatively recent and often feature Counted thread embroidery like hardanger, cross-stitch and Blackwork. <ref>{{Cite web |url=https://www.needlenthread.com/2007/06/biscornu-needlework-oddity-thats-really.html/|title=Biscornu: a needlework oddity|work=Mary Corbet|date=2025-10-29}}</ref> A button is commonly placed in the center of the cushion to give it a pleasing tufted look.<ref name=":1">{{Cite web |last= |date=2017-04-27 |title=Biscornu |url=https://www.trc-leiden.nl/trc-needles/individual-textiles-and-textile-types/accessories/biscornu |access-date=2022-10-19 |website=TRC Needles |publisher=Textile Research Center Leiden |language=en-gb}}</ref> Beads, ribbons, tassels and other objects can be used for decoration.<ref name="Watts" /> Biscornu typically fits in the palm of the hand. Although larger 15-sided versions are also made.

Mathematically, two squares joined together in the pattern of a biscornu will form the boundary of a unique convex polyhedron, by Alexandrov's uniqueness theorem.<ref name=":0" /><ref>{{cite book | last1 = Devadoss | first1 = Satyan L. | author1-link = Satyan Devadoss | last2 = O'Rourke | first2 = Joseph | author2-link = Joseph O'Rourke (professor) | isbn = 978-0-691-14553-2 | mr = 2790764 | pages = 185 | publisher = Princeton University Press | location = Princeton, NJ | title = Discrete and Computational Geometry | url = https://books.google.com/books?id=InJL6iAaIQQC&pg=PA185 | year = 2011}}.</ref> In the case of a biscornu, this polyhedron is a flattened square antiprism, with ten faces: two smaller squares (diagonally inset into the squares from which the shape is formed) and eight isosceles right triangles (the corners of its original squares) around the sides. However an actual biscornu will have a somewhat more rounded shape than this polyhedron.

==See also== {{Wiktionary|Biscornu}} *Paper bag problem, on the shape of a pillow formed by hemming two squares together corner-to-corner and edge-to-edge

==References== {{Reflist}}

Category:Embroidery