Unsanforized


In contrast, unsanforized denim — sometimes referred to as raw, loomstate, shrink-to-fit, or dry denim — skips the sanforization process. This means a pair of raw jeans is guaranteed to shrink after an initial soak and will likely shrink further during the first few washes. Because this shrinkage can be unpredictable depending on the weave, unsanforized garments can be tricky to size — even for experienced denimheads.
Still, there are many reasons enthusiasts are drawn to raw denim. These fabrics often have more texture and character, preserving all the charm of shuttle-loom-woven denim that can sometimes be subdued by sanforization.

The potential for shrinkage also offers an opportunity for a more personalised fit — so while there's always an element of risk when sizing raw denim, get it right, and the garment will mould to the wearer's body like no other.
While we do produce raw, unsanforized denim, Iron Heart founder Haraki-san often favours lightly or fully sanforized fabrics for the even, smooth hand and predictable shrinkage they offer.

One-Washed


However, there’s another factor to consider: one-washing. At the final stage of production, most completed Iron Heart garments are aggressively washed in industrial machines. This process removes any residual shrinkage that might otherwise occur during the first soak or wash after purchase, and it also softens the fabric for an easier break-in.


Now, here’s where things can get confusing — one-washing can apply to both sanforized and unsanforized fabrics. For example, our 25oz XHS denim is sanforized but unwashed, while our 19oz left-hand twill denim (except for the raw 19oz Type III jacket) is unsanforized but one-washed. In both cases, the fabric is partially pre-shrunk, but you may still experience some shrinkage with soaking and washing. Our 25oz denim, in particular, offers a user-friendly middle ground between fully pre-shrunk and true “shrink-to-fit” jeans.
The only core denim in the Iron Heart lineup that is always both unsanforized and unwashed — i.e., true raw/loomstate — is our Ultra Heavy Raw fabric.

This denim weighs 21oz per square yard fresh from the loom but tightens to a heavyweight 23oz after soaking and washing. As the fabric becomes denser, it naturally shrinks — if you’re looking for an authentic “shrink-to-fit” experience, this is the Iron Heart denim for you.
Most commonly, our denim is both sanforized and one-washed, which eliminates nearly all potential for garment shrinkage. However, please note that this only holds true when the garment is washed according to our care guidelines. Boil soaking, hot washing, or tumble drying your jeans, jacket, or shirt can still cause noticeable shrinkage — regardless of whether the denim is sanforized or not.

What are the benefits of sanforization and one-washing?
While many in the selvedge scene view raw denim as the more “authentic” option, we believe the benefits of sanforized and one-washed fabrics often outweigh the perceived cool factor of loomstate weaves. We’ve already touched on some of these advantages, but let’s explore them in more depth.






Predictable sizing


Firstly, it's much easier to accurately choose the right size when a garment or fabric is pre-shrunk. While most denim will stretch slightly under tension — most noticeably at the waist of a pair of jeans — this is typically the only factor you'll need to consider with sanforized, one-washed denim. This means that if you order a pair of jeans from us and they don't fit upon delivery, we'll happily exchange them or offer a refund (see our returns policy for details).

On the flip side, with raw denim, you not only need to account for potential stretch but also the shrinkage that occurs through soaking and washing. Unfortunately — as with most clothing brands — once a garment has been soaked or washed, it’s no longer eligible for return or exchange. We aim to provide the most accurate sizing charts possible, along with detailed notes on stretch and shrinkage. But if you get the sizing wrong with raw denim, it can be a costly mistake.