Know Your Twills – 3×1, 2×1, and Plain Weave

Here at Heddels we’ve gone over subjects like bar tacks and flat-felled seams, so it’s only natural that we go to the core of denim–the weave. Denim weight is a fairly known commodity; the higher the ounce weight in denim, the heavier and more durable the fabric.

It may not be as commonly known that the weave is what helps determine the weight in ounces. 3×1, 2×1, and 1×1 or plain weave are the terms to know, so let’s go through them below.


Weft on a 3x1 pair of Naked & Famous denim.

Weft on a 3×1 pair of Naked & Famous denim.

3×1 is the most common in selvedge denim, chiefly because any denim over a 10.5 Oz. per square yard weight is 3×1. What the numbers describe is the number of warp threads versus weft threads. For 3×1, there are 3 warp threads for every weft thread.


If you closely inspect your favorite pair of selvedge denim that is at least 10.5 Oz. in weight, you’ll likely see three threads crossing over every one weft thread. 3×1 is the most common simply because it is the sturdiest weave; denim is a fabric rooted in workwear, so it’s only natural to have it be as durable as possible.



A lightweight 2×1 denim from Pacific Blue

As you may have guessed, 2×1 is just two warp threads for every weft thread. We’ve covered summer weight denim options at Heddels before, which typically clock in at less than 10.5 Oz.

These pairs of denim are likely woven using a 2×1 weave. For those of you who have worn heavyweight denim in the summer, it can get rather…hot down there. A 2×1 provides the durability that denim is known for, while making it more breathable.

Plain Weave


A plainweave chambray from The Hill-Side

Plain weave is a simple way of saying a 1×1 weave. The warp and weft are aligned so that they form a simple criss-cross pattern. This method is the most simple way for cloth to be woven, as well as one of the cheapest.

By varying the tension of the threads, weavers can make the resulting fabric tighter or looser and stronger or more breathable. Basketweave is a well-known variation of the plain weave method.