The Skinny on Denim

What is Denim?

I am pretty sure that almost everyone in  Canada owns at least one piece of clothing made of denim. Heck, they even call wearing a denim top with denim trousers a Canadian Tuxedo. I’d take offense, but I love denim so much I’ll take it as a compliment. Plus, it would be worse if it referred to wearing camouflage and plaid together. Which can be forgiven as it happens rarely and most often during hunting season.

We had to take a textile classes at school; and on the first day of classes, I thought the class was going to be dry and boring compared to my other classes like Drape, Design, and Patternmaking.  I quickly realized that to be a good designer or to create fabulous garments you need to know the characteristics of textiles. So I thought that since this month’s design challenge on the blog is a denim challenge that I should brush up on my knowledge of denim.

Denim is a warp faced fabric with a twill weave. It is made of cotton or a cotton/polyester blend and often has other fibers such as Spandex added to it to change its properties.

 

Warp-Faced Twill Weave….What?

Okay I know “warp-faced twill weave” sounds complicated but it is pretty straightforward. Once you learn more about the weave, you will understand why denim behaves the way it does and why denim, and jeans specifically, are so darn popular.

To understand denim’s twill weave, it helps to compare it to 100% cotton fabrics like gingham or broadcloth. Gingham and broadcloth are two fabrics with a plain weave. This weave is much like the paper weaving you did when you were little in school. Back then you took a strip of paper and moved it horizontally over and under the lengthwise pieces of paper until you got to the edge. It is the same principal with a plain weave fabric (see the photo above.) The vertical yarns are the warp yarns. These yarns run parallel to the selvedge. The yarns that travel back and forth horizontally are the weft or filling yarns, and they go over and under the warp yarns in a 1/1 pattern.

Wales and Floats

Denim is made of a twill weave which is slightly different than a plain weave. In denim fabric, the filling yarns do not go over one warp yarn and then under the next in a 1/1 pattern but instead follow a 2/1 pattern.* This means that the filling yarn travels horizontally under two warp yarns and over one and then continues to repeat this pattern to the end where it then comes back following the same 2/1 pattern just moved one to the right or left (see the photo above.)  This makes it seem like there is a diagonal line travelling across the fabric. This diagonal line is called a wale.

Floats are when one yarn travels over two or more yarns. In denim fabric,  there are more filling floats than warp floats on the right side of the fabric. This means you will see more of the blue warp yarns as it can be seen on the right-side of the fabric more than the white filling yarns. It is for this reason why denim is darker on the right side (or technical face) than on the wrong side.

 

What Makes a Twill Weave so Strong and Durable?

Warp yarns normally have a higher twist than filling yarns as they are the lengthwise yarns that are pulled tight by the loom and the weft or filling yarns are the ones that travel back and forth, and over and under the warp yarns. As denim has more warp yarns on the face of the fabric, it is typically stronger and less likely to show wear or tear compared to a plain weave fabric.

Okay, I know I have thrown in a lot of technical terms in this post like twill weave, warp-faced, float, and wale. But there is one more word you need to know to help understand why a twill weave can be more durable than a plain weave; interlacings. Interlacings happen each time a yarn travel from the top of the fabric to the bottom or the bottom to the top. A plain weave has more interlacings whereas a twill weave has less. If you look at the photo above you will notice see how the plain weave contains fewer yarns as it needs more room for the interlacings.

Imagine for a moment that you own a long skinny block of land and want to build houses on it. You are required by the town planner to have a road linking the streets in front and behind your land. If you have more streets cutting across your strip of land, you will be able to fit fewer houses in the same space. These streets that let the cars travel from in front of your houses to behind them, much like interlacings in a fabric’s weave, take up room. I hope I did not loose you with my strange, slightly simplified analogy. But the interlacings in a weave are important as more yarns in a piece of fabric tends to make the fabric stronger, more resistant to abrasion, increases its durability, and wind-resistance. Having all those threads packed together also makes it less likely that dirt particles will get stuck in the fabric too. And aren’t these some of the reasons we love denim.

Denim Characteristics Review

Cotton (or denim typical cotton blends)

• Absorbs moisture – This and the weight of the fabric is why it takes so long to dry.
• Retains heat – Due to the tight twill weave and cotton’s natural properties
• Easy to Clean – Can be washed regularly but care must be taken to pre-shrink fabric.

Twill Weave (Compare to a balanced plain weave)

• Has a diagonal pattern on its surface called a wale. It is caused by floats -when the woven yarns “float over yarns instead of following and over under pattern of a plain weave. This weave also makes it less likely to wrinkle and to trap dirt.
• More yarns packed closer together due to fewer interlacings. This allows the fabric to be more resistant to abrasion, wind, dirt and tearing. It makes the fabric stronger and more durable.

Warp Faced

• More of the warp yarns are on the surface of the garment, as these yarns have a higher twist it makes denim more resistant to abrasion.
• As the warp yarns are typically blue, there will be more blue yarns visible on the right side of the fabric. Conversely, the wrong side of the fabric will show more filling (white) yarns.

I Would Love to Hear From You

I would love to hear from you if you found this post useful. If you did, I can do similar posts in the future. If most of you fell asleep halfway through this post, I will stick to articles about design, patternmaking, and sewing. I am still experimenting with what content to provide here so I would love any feedback, especially constructive criticism, you might have regarding this post or the blog. Feel free to comment in the comments, through my contact form, or on social media. I am Duelling Designs on all platforms and eager to hear from you.

We haven’t covered everything about denim, but we have made a great start. My next post, The Different Between Denim and Jean, will discuss a little about how denim is dyed as denim’s colour, and its fade pattern is another characteristic that makes us love denim.

If you would like some denim inspiration, I have created a couple of Pinterest boards that are full of great denim ideas.

*There are other types of twill weaves like 3/1, 2/2, or 3/3. I did not want to confuse things, so I just mentioned the most popular twill weave used in making denim. On a mechanical loom, you do not move the filling yarns up on over the warp yarns, but the warp yarns move up and down on parts called harnesses. The filling yarns instead go straight across on a shuttle when the harness move up and down on the loom, and this is where the fraction comes from.

I am not a textile expert; I am just sharing the things I learn along my journey to live a happy and creative life. If anything I wrote here or in any other post needs to be corrected or clarified please contact me on the blog’s contact page as I appreciate anyone who helps me learn more.