Fabric Design 101 :: Warp, Weft, Selvage & Their Influence On Colourways

This short article will tell you what the warp, weft and selvage of a fabric are. Then how easily, or not, colours in each can be changed in handwoven fabrics.

The Americanism ‘101’ normally means the introductory, grounding ‘lesson/lecture’ in a subject. So most interior designers already know that:

– WEFT is the crosswise thread that inter­laces with the warp threads on a woven fabric. ie it is the thread that goes from LEFT to right. (Weft and Left rhyme so that’s how you remember it)

– WARP is group of yarns placed first on a loom in weaving. These can be 100s of metres long running throughout the entire roll of fabric that you eventually buy.  Warp runs parallel to the selvage, forming the length of the fabric. The filling threads are interlaced over and under the warp threads in a pattern or weave.

– SELVAGE is the long, outer, finished edge of both sides of a woven fabric that does not ravel because the filling yarns wrap around the warp yarns. It may also be called self-edge or selvedge.

OK, so now if we take a few steps back to the design of a simple woven fabric. KOTHEA, for example, produce handwoven linens to order, often in small quantities. How do we plan to do this? One clever trick is to keep a plain, natural or white coloured yarn in the warp and then introduce colours into the weft as needed. Why? Much of the time consuming process of setting up a loom is in setting up the yarns for the warp. Yarns for the weft can be changed relatively easily without changing the warp yarn.

Simple but great for our customers who need the exclusivity and beauty of handwoven linens and who do not want the large minimum order quantities that can come with that.

Warp and Weft in Specification

Warp and weft matter beyond colour. On a woven fabric the warp runs the length of the roll, parallel to the selvedge, and the weft runs across the width from selvedge to selvedge. Fabric width is therefore the weft dimension, usually around 137 to 140 cm for upholstery and curtain fabrics, and length is bought along the warp.

Pile and pattern direction. On velvet and other pile fabrics, the pile lies in one direction along the warp. All pieces on a job must be cut with the pile running the same way, or the panels will look different shades. Patterns are also designed to read along the warp, which is why pattern repeats are given as vertical and horizontal measurements. For the method, see our pattern matching guide.

Railroading. A railroaded fabric is used turned through 90 degrees, so the warp runs horizontally across the piece. This lets an upholsterer cover a long sofa back or seat without a seam. Only some fabrics can be railroaded: a directional pattern or a pile fabric may look wrong turned on its side, so confirm with the supplier before specifying it.

Strength and stretch. Warp yarns are held under tension on the loom and are usually the stronger set, so many fabrics are slightly more stable along the warp than across the weft. Upholsterers take this into account when deciding how to cut and pull a fabric.

Quick answers

What is warp and weft in fabric?
Warp and weft are the two sets of yarns in a woven fabric. The warp yarns run the length of the fabric, parallel to the selvedge, and are set up on the loom first. The weft yarns run across the width, interlacing over and under the warp. A simple way to remember it: weft goes from left to right.

What is the selvedge of a fabric?
The selvedge, also spelt selvage, is the finished edge on each side of a woven fabric, where the weft yarns turn back around the outer warp yarns. It stops the fabric fraying and runs parallel to the warp along the length of the roll.

What does railroaded fabric mean?
Railroaded fabric is fabric used turned through 90 degrees, so the warp runs horizontally across the piece instead of vertically. It lets an upholsterer cover a long sofa without a seam. Directional patterns and pile fabrics are often unsuitable for railroading, so confirm with the supplier first.

For definitions of other weaving and specification terms, see our fabric specification glossary.