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What is Sanforization and Why Does It Matter?

You have probably not heard of Sanford Lockwood Cluett, but he is the man responsible for assuring your $300.00 Raleigh’s still fit after their long-awaited first wash.  That’s right! Having spent his youth wrangling alligators in Florida, leaning the Seminole language and working in the engineer corps for the Spanish-American War, Cluett invented the magical process of sanforization in 1930.

Heddels's Guide To Sanforization

What is Sanforization?

Sanforization is the process of treating cotton fabrics to reduce the amount of shrinkage that would otherwise occur after the first wash.  During the sanforization process, the fabric is fed into a sanforizing machine where it is treated with water or steam to promote shrinkage, then pressed against a heated rubber band to relax and recontract 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.

Heddels's Guide To Sanforization

Cross-section of a Sanforization Machine (Photo Courtesy of SecondHandTextileMachinery)

What does it have to do with Raw Denim?

Denim comes in two types: That which has been sanforized, and that which has not (AKA “Unsanforized denim”). Unsanforized denim will shrink a few inches in the waist and inseam when it is first soaked, hence Levi’s aptly-named “Shrink-To-Fit” denim. Sanforized denim shrinks is generally considered to be “pre-shrunk”, and therefore does not need to be sized up or down accordingly.

A degree of care is necessary when washing sanforized raw denim for the first time, because there is still a chance for minimal shrinkage, but a whole preliminary process is necessary with unsanforized denim before even the first wear.  To many denim heads, soaking is nothing short of a ceremonial step in the long-term process of breaking-in and personalization.

Soaking unsanforized raw denim is, more or less, sanforizing your own jeans, assuring the cotton fibers of your denim are heated and relaxed in order to save the headache of shrinking your jeans beyond your belt line in subsequent washes. For more information on how to soak your jeans (whether they’re sanforized or not), see our article on this critical first step.

Thanks to Sanford Lockwood Cluett and his patented sanforization process, not every new pair of jeans needs to be soaked and treated, which can save raw denim geeks a lot of headache and frustration since they can buy jeans without worrying if they’ll fit post-wash.