I’m going to be talking about different types of cotton in upcoming posts, and I’ll be posting the much-anticipated tutorial on trueing up your fabric. But first, we have to get a good grounding in basic weaving terms. Ready? There will be a quiz later. Kidding. Unless you want a quiz.
Warp and weft: Warp refers to the yarns set up on a loom, weft refers to the filling yarns. The back-and-forth filling with the weft yarn, usually at a 90-degree angle, creates the selvedge. So, warp = lengthwise, weft = widthwise. I used to have so much trouble remembering which is which — does anyone have a good mnemonic? How about “Weft goes left and right?”)
There are three basic weaves.
Plain weave: the basic 1-1 criss-cross checkerboard of warp and weft yarns (as seen in the top image). Most commerical fabrics, including most quilting cottons, are plain weaves. Plain weaves tear easily.
Satin weave: Either the warp or weft yarns float over four or more strands of the crosswise yarn before going under one yarn and back up. If the warp yarn is the floating yarn, the fabric is called “satin,” if it’s the weft yarns floating, the fabric is called “sateen.” The traveling yarns create a more lustrous appearance and the fabric drapes better than plain weaves, but they are not durable.
Twill weave: The weft floats across two or more weft yarns, and each weft row offsets the pattern over a predetermined step, creating a diagonal pattern. The diagonal pattern can be reversed at intervals; these are called “broken twills”: herringbone, chevrons, zigzags, and houndstooth are all broken twill patterns. A steeper diagonal means higher quality, stronger fabric. The fabric is durable and difficult to tear, and usually has a rather stiff drape.
All About Cotton: A Fabric Dictionary & Swatchbook (Fabric Reference Series, Vol. 2) by Julie Parker, Rain City Publishing, 1998
From Fiber to Fabric: The Essential Guide to Quiltmaking Textiles, by Harriet Hargrave, 1996