I get the question all the time what is the difference between denim and jeans. The simplest way to answer that question is that denim is the material and jeans are the garments made from that material.

So what then is denim you ask? Allow me to answer as briefly and as simply as I can. Denim is really all about the way the fabric is woven. It is a durable twill fabric which means there is a diagonal pattern easily seen on the reverse side of the fabric. See image 1

Image 1: You can see the diagonal pattern here making it a twill fabric

The denim I generally use is a heavier weight (the raw Classic Indigos are 14.5ozs - but we’ll discuss ounces in a later post), a 3 by 1 weave.That means there are 3 warp threads (the threads that run up and down) to 1 weft thread (the thread that runs long ways). The warp threads are dyed with Indigo and the weft threads are left undyed so they remain white. That’s why the facing or right side of the fabric is blue while the other side is white. You can easily see this when you cuff your jeans. See image 2

Image 2: The facing is blue while the other side is white.

Fun fact! Genoese sailors (see pic 3) wore denim because it was such a durable fabric and also because it was easier to repair than other materials. When the Indigo warp threads would rip and wear away, many times the weft threads would remain making repairs much simpler. I’m sure you have noticed this when your jeans have ripped. See image 4.

Image 3: This image is most likely not of a sailor although it was very common to have children working on ships at this time, however it is most likely what the denim garments looked like, including all of the small repairs.

Image 4: See the weft thread remaining making it easier to repair.