From The Denim Hunters
‘Selvedge’ is the name for the higher-quality, harder-to-produce type of denim that is typically sold and worn unwashed. You can spot it on the cuffs of jeans. If they’ve got a clean look with edges that are usually white/red/white, it’s selvedge denim.
But what is selvedge denim? Why is it more expensive than ‘normal’ denim? Is it worth it? And is selvedge denim better?
Selvedge actually ought to be spelt ‘self-edge.’ The term refers to the self-finished edges of shuttle-loomed fabric. Here we’re talking about weaving, which we must understand to know what selvedge is.
The yarn that runs across—known as the weft—is threaded over and under the yarn that runs downwards, which is called the warp.
The Two Ways to Weave Denim
There are two ways to weave denim: with or without a shuttle. Weaving with a shuttle is the old school way.
The shuttle is essential; it threads the weft through the warp shed. As the weft is continuously passed back and forth, the edges of the fabric are self-finished, which is why it’s called ‘selvedge.’
Hurling a shuttle back and forth is a relatively time-consuming process that creates a bottleneck in terms of production speed. So, when they need to weave faster (and cheaper), denim makers use shuttleless weaving machines.
Shuttleless weaving is most commonly done with a projectile loom. Instead of a shuttle, a small metal device that looks like a bullet (hence the name) carries the weft across the shed.
Shuttleless looms usually weave at least four times faster than shuttle looms. And because the weaving frame can be widened, production capacity is up to 10 times higher.
In other words, you can get 10 times as much denim per hour when it’s not selvedge, and that obviously affects the price.
The fact that all shuttle looms are old and need a lot of care and maintenance to keep them weaving is another important cost factor.