Seams joing the squares may be eased; that is, there are more squares on one side of the join than on the other. The extra length is distributed evenly along the seam, creating fullness without discrete pleats.
Similar methods
Darning loom with a shedding mechanism.
Darning looms are similar to pin weaving, but instead of being wrapped around pins, three of the selvages are stitched into the cloth being repaired. The fourth is wrapped around a revolving-hood mechanism which, when rotated, forms a shed and countershed, making plain tabby weaves much faster. When finished, the hooks are removed, and the fourth selvage is usually stitched to the cloth.
Wikimedia Commons has media related to Pin weaving.
Publications
Early twentieth-century
Original Loomette Weaves, Revised edition with improved joining method described, by Loomette Studios. Public-domain fulltext.
The Loomette Handbook; New weaves, vogues, and suggestions, by Loomette Studios. Public-domain fulltext.
See Commons:Category:Pin-weaving publications for more public-domain books
See also eLoomaNation for more free fulltexts
21st-century
Stump, Margaret (2002). Weavies One. PO Box 255, Buffalo Lake, Minnesota, 55314, self-published.
Spencer, Hazel (2003). Weaving On Hazel Rose Looms. Rt. 2, Box 4792, Trinity Center, California, 96091, self-published.
Matthiessen, Barbara (2008). Small loom & freeform weaving : five ways to weave. Minneapolis, MN: Creative Pub. International. p. 128. ISBN 978-1-58923-361-4.
Trent, Jana (2009-06-11). "Triangle or Rectangle? [shawl pattern]". www.weavezine.com.
Stump, Margaret (2014). Pin loom weaving : 40 projects for tiny hand looms (First ed.). Mechanicsburg, PA: Stackpole Books. ISBN 9780811712484.
Correa, Florencia Campos (2015). 100 pin loom squares (First U.S. ed.). New York. ISBN 9781250059093.{{cite book}}: CS1 maint: location missing publisher (link)
Stump, Margaret (2017). Pin loom weaving to go : 30 projects for portable weaving (First ed.). Guilford, Connecticut: Stackpole Books. ISBN 9780811716130.
Stump, Margaret (2019). Adorable beasts : 30 pin loom animals + 4 playscapes. Lanham, MD: Stackpole Books. ISBN 9780811737753.