Raw Denim Shrinkage: Sanforized vs Unsanforized Denim

What is sanforized denim?

Sanforized denim refers to denim that has been pre-shrunk using a mechanical process before it is cut and sewn into jeans. The process involves stretching the fabric under tension while it is wet, then drying it, which sets the fibers and reduces the amount of additional shrinkage the fabric will experience in later washes. The term comes from the Sanforized trademark, which originated with the Sanforizing process developed in the early 20th century.

In practice, sanforized denim shrinks very little after you buy it, usually just a small amount in the first wash. This makes it the standard for most retail jeans, because it allows manufacturers to sell a pair that will fit consistently after the customer takes it home. If you are looking for a straightforward purchase with minimal surprises, sanforized jeans are the easier choice. For more background on how denim is constructed, see our denim fabric construction guide.

What is unsanforized denim?

Unsanforized denim, sometimes called shrink-to-fit denim, has not gone through the pre-shrinking process. The fabric is woven and then cut and sewn directly, so it contains the natural tension of the cotton fibers. When you first wash a pair of unsanforized jeans, they will shrink significantly, often changing the fit in length, waist, and elsewhere.

This shrinking is not a flaw; it is an intentional characteristic embraced by raw denim enthusiasts. The idea is to buy a larger size and then wash or soak the jeans so they shrink to conform to your body. The result can be a better personalized fit, but it also requires more care and attention. If you want to explore the broader world of raw denim, read our raw denim and selvedge guide.

How much do they shrink after washing?

Sanforized denim will shrink only a small amount, typically less than 5% in any dimension. In practice, that means you might notice the waist and inseam tighten slightly after the first wash, but the change is not dramatic. Unsanforized denim, by contrast, can shrink more noticeably, often in the range of 5% to 10% or more, depending on the fabric weight, the weave, and the washing method. Over time, as the jeans are worn and washed repeatedly, the fabric relaxes and stretches back out in areas like the waist, but the length and other dimensions tend to stay close to the post-wash size.

The exact amount of shrinkage depends on several factors, including the temperature of the water, the agitation of the wash, and whether you use a dryer. Hot water and high heat will cause more shrinkage than cold water and air drying. Cotton is a natural fiber that responds to heat and moisture, and the USDA Agricultural Research Service has studied how cotton fibers behave under various conditions. For practical care advice, see our how to care for jeans guide.

How to shrink unsanforized jeans (if you choose them)

If you decide to go with unsanforized denim, you will need to shrink it to size. Here is a common approach: soak the jeans in warm water for 30 to 60 minutes, then wear them while they dry to let the fabric mold to your body. Alternatively, you can machine wash them cold and hang them to dry. The key is to avoid extreme heat, which can cause excessive shrinkage and also fade the indigo more quickly.

Some people prefer to do a warm soak rather than a full wash to minimize dye loss. After the first soak, the jeans will have shrunk, and any further washes will cause minimal additional change. Remember that unsanforized denim will stretch back out in the waist and hips as you wear them, so size down accordingly. Our raw denim break-in guide has more details on what to expect during the initial break-in period.

• Check the care label for specific instructions, since some raw denim is also sanforized but treated differently.
• Use cold water for a more gentle shrink, warm water for a more pronounced effect.
• Wear the jeans while damp to let them conform to your body shape.
• Avoid the dryer unless you want maximum shrinkage, which may be hard to control.

Which should you choose?

Your choice comes down to how much effort you want to invest. Sanforized denim is the practical option for most people: it fits well out of the store, shrinks minimally, and can be washed without worrying about dramatic changes. Unsanforized denim appeals to those who enjoy a project, want a custom fit, or prize the creases and fades that develop from a shrink-to-fit process.

If you are new to raw denim, starting with a sanforized pair is a good way to learn the basics of care without the risk of ruining a pair that shrinks too much. If you are experienced and want to dial in the perfect fit, unsanforized gives you that control. For fit guidance, see our jeans fit types comparison.

What to pick for your use

Questions

Can I shrink sanforized jeans if they are slightly too big?

Yes, but only slightly. Sanforized denim has already undergone a pre-shrinking process, so further shrinkage will be limited. A hot wash and dryer might tighten the waist a little, but do not expect a dramatic change. Better to get them tailored or swap for a smaller size.

How much does unsanforized denim shrink after the first wash?

The shrinkage varies with the fabric and washing method, but it is often enough to reduce the waist and inseam by several centimeters. The exact percentage is not fixed, so it is wise to buy a size larger than you normally wear and then wash to fit.

Is unsanforized denim better quality than sanforized?

Quality is not determined by whether denim is sanforized. Both can be made from high-quality fiber and weave. Unsanforized denim is often associated with raw selvedge styles, but you can find excellent sanforized denim as well. Focus on fabric weight, construction, and the reputation of the manufacturer.

How do I know if my jeans are sanforized or unsanforized?

Check the care label or the product description. Many brands state if the denim is sanforized or shrink-to-fit. If there is no indication, you can look for the Sanforized trademark, though not all pre-shrunk denim carries the label. When in doubt, cold wash and air dry to minimize shrinkage.