What’s the Difference Between Warp and Fill?

Warp and Fill - What's the Difference?


At Acadian Industrial Textiles, we are proud to be a source of knowledge and information to help our customers find the right products for their customers.

In this article, we’ll talk a little bit about warp and fill, and why it’s important to know the difference between the two. 

What are warp and fill?

Warp and fill (also called weft) refer to the orientation of woven fabric. The warp direction refers to the threads that run the length of the fabric. This is also known as the machine direction because it’s the direction the threads run on the loom. It forms the longer dimension of the fabric and is the direction of the roll length.

The fill, or weft, refers to the yarns that are pulled and inserted perpendicularly to the warp yarns across the width of the fabric. You can see the difference between these in the diagram below.




A little bit of trivia: warp comes from the Old Norse word, varp, which means “the cast of a net.” The “net” of warp threads catch the fill threads to create a secure weave. Weft is from an Old English word, wefan, which means “to weave.”

Knitted and other nonwoven fabrics do not have warp and fill orientations.

Why are warp and fill important?

Warp and fill are tested separately in fabric strength tests. When shopping different fabrics, it’s important to know which direction a strength test was conducted in so you can compare like measurements.

For example, Acadian’s tennis windscreen’s tensile strength is 290 lbs. across warp, and 140 lbs. across fill. If you compared this fabric’s warp strength to another fabric’s fill strength, it wouldn’t be an accurate picture of their differences.

Read more about tensile strength here and more about tear strength here.

How do warp and fill affect my products?

Depending on the application, warp and fill are critical to pay attention to. If the fabric will be stretched or pulled in a particular direction, make sure it is strong enough to withstand the force in that orientation. This is especially important in applications like truck covers, containment, and shade fabric.

What if I still need help?

That’s why we’re here! We are more than happy to help you choose the right fabric for a customer or answer any other questions you have about fabric specifications.