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Unsanforized vs. Sanforized Denim

We break down the differences between sanforized and unsanforized denim, from shrinkage to texture and fading potential.

Young Lee

When shopping for raw denim, you will often see the terms sanforized and unsanforized. Sanforization is a process that removes most of the shrinkage from an otherwise raw denim fabric. Handy, right? Yes. But sanforization does change the appearance of raw denim, leading some denim heads to prefer unsanforized fabrics.

If you’re confused about the differences between sanforized and unsanforized selvedge, this article is for you. We’ll give you the differences between sanforized and unsanforized denim, from shrinkage to texture, fading potential, and much more.

What is Sanforization?

You have probably not heard of Sanford Lockwood Cluett, but he is the man responsible for assuring your $300 jeans won’t shrink on you. Having spent his youth wrangling alligators in Florida and working in the engineer corps for the Spanish-American War, Cluett invented the magical process of sanforization in 1930.

Sanforization is the process of treating cotton fabrics to reduce the amount of shrinkage that would otherwise occur after their first wash/soak. During the sanforization process, the roll of fabric is fed into a sanforizing machine where it is treated with water or steam to promote shrinkage, and then pressed against a heated rubber band to relax and re-contract the fibers. This ensures the fabric will shrink no more than 5% after it is washed for the first time, as opposed to a potential 10% for unsanforized fabrics.

Key points: 

• Sanforization is a fabric-treating process invented by Sanford Cluett in 1930

• The process uses water and/or steam to promote shrinkage of the raw fabric and then heat to relax the fibers

• Sanforization typically ensures shrinkage of no more than 5%, compared to 10% or more in unsanforized fabrics

• Sanforization is common in the world of denim, including raw selvedge denim

What Does Unsanforized Mean?

With that considered, unsanforized denim is simply denim that did not go through the sanforization process and therefore will shrink when washed or soaked. Unsanforized denim can also be referred to as “shrink-to-fit” or STF, which is a term used by Levi’s for their unsanforized jeans. Occasionally the term “loomstate” (which means that the fabric is unaltered and untreated after being woven) will be used to describe unsanforized denim.

The general rule with unsanforized denim is that you should give it a soak for a certain amount of time to allow it to shrink before you start wearing the jeans. This is why brands and stores will suggest sizing up one or two sizes with unsanforized denim. Sizing up will allow the denim to shrink to the right size when soaked for the first time.

/ In Partnership with Blue Beach Denim /

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Unsanforized vs. Sanforized Denim

So, if sanforization removes the fuss of post-purchase shrinkage, why would you bother with unsanforized? Why are people on Reddit telling me unsanforized denim is better? Will sanforized jeans still fade? Whether or not unsanforized denim is “better” is completely subjective, but we’ll dive a little bit deeper into how unsanforized and sanforized denim differ from one — other than the shrinking aspect.

As mentioned before, the sanforizing process applies heat, moisture, and pressure to the fabric to shrink and stretch it repeatedly. While this process is very effective in removing most of the shrinkage from the fabric, it can also flatten the denim and cause it to lose some of its rougher. more rugged characteristics. Some mills will even singe the hairs off the denim and mercerize it to achieve a more uniform and lustrous look. The result is often a smoother-looking denim that is ready to wear right away — and still can fade very well with wear — but ultimately,  fabric does lose some of its raw character as shown in the image above.

Unsanforized and loomstate denim retains all the qualities of the raw woven fabric caused by the type of cotton being used, how the yarn is spun, dyed, etc. These different characteristics are accentuated as the denim ages and fades, with unsanforized denim often fading faster than their sanforized counterparts.

With that in mind, it’s important to note that not all unsanforized denim has the same characteristics and fading properties. These qualities will vary from mill to mill. In general, most mills that offer unsanforized denim are very specialized in creating high-quality denim, with many working directly with brands to create proprietary denim that can become unique calling cards for each brand. some brands, e.g. The Flat Head or Warehouse & Co., might even develop unsanforized fabrics that are flat, unhairy, and uniform, all in the name of reproduction. The denim game is big and diverse, so don’t ever think one rule applies to all.

The same goes for sanforized denim. There are some brands out there, like Iron Heart, who use some of the most unique and nuanced sanforized fabrics out there, all of which produce some killer fades. Just check the examples at the end of this article!

Key Points: 

• Sanforized denim is pre-shrunk but typically flatter in texture, sometimes with a subtle sheen

• Unsanforized denim can be hairier, more textured, and retain more characteristics from the loom it was woven on

• Not all sanforized or unsanforized denim is the same, the finished fabric always differs from mill to mill, spec to spec

• Unsanforized denim can develop more unique fades and can fade faster due to its rough and unprocessed nature

• Sanforized denim still fades beautifully

Risks of Unsanforized Denim & How to Avoid Them (Incl. One Wash Unsanforized Denim)

The idea of unsanforized denim is great, especially for those looking for more unique and distinctive fabrics. But it’s not without some drawbacks. Because the denim can shrink anywhere from 1-2 sizes, there can be a level of uncertainty when it comes to what size to choose. If unsure, always reach out to the retailer and ask for the shrinkage expectancy. If they have no info, try Reddit to see if anyone else has had the same denim. If in doubt, plan for 10% shrinkage to be on the safe side (better too big than too small, right?). If they don’t shrink to size with a warm soak, can try going hotter.

Even with that information, there’s still a chance that the denim will shrink differently from expected, not only from the initial soak/wash but also after the first wash after wearing. Without sounding overdramatic, it’s a try-at-your-own-risk situation, especially if you lack experience with it.

Many brands offer unsanforized denim garments that are ‘one washed‘ to remove some of the shrink and alleviate uncertainty. In these cases, there will be no need to soak the denim again since the brand or store has taken care of that already.

Key Points: 

• Unsanforized denim will shrink 1-2 sizes, potentially more

• Ask the retailer about the expected shrinkage, if not ask the raw denim community if anyone has experience with the fabric or reach out to the brand directly

• Some brands one wash unsanforized denim garments to remove most of the shrink

Final Thoughts & Fade Examples

It can be argued that unsanforized denim is desirable not just because it’s unsanforized but also because the brands and mills that offer them are some of the best in the industry. Any denim coming from those mills — sanforized or not —would be of the highest quality. For many people, the tribulation of sizing and shrinking unsanforized denim properly is actually a desired additional step in raw denim journey.

If you take a look at our Fade Friday section, you’ll see some great examples of beautifully worn-in jeans and jackets that use sanforized and unsanforized denim.  In the end, whether it’s unsanforized or sanforized denim, it’s important to remember that all the fuss about denim is all for nothing if you’re not wearing it so do your research on the brands, ask questions, make a choice, and start wearing your jeans.

Sanforized Denim Fade Examples:

Unsanforized Denim Fade Examples:

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Diving Into Selvedge Denim – An In-Depth Look

The White Oak Economy – How Millennials are Changing Retail