The Truth About Silk Shrinkage: How Important Is Pre-Shrinkage Treatment?

I chose the size chart exactly, but it shrank after washing, and I can't wear it anymore. We've seen countless comments like this under our silk product reviews over the years. Most people's first reaction is to blame "bad fabric," but the truth is more complex-the key is whether the fabric has undergone proper pre-shrinking treatment.

Shrinking of silk is a natural characteristic of the fiber. Mulberry silk consists of fibroin and sericin. These components help the fibers to become thicker and shorter after the fibers have absorbed water which in the natural course leads to the shrinking. To cite the most prominent reason, silk is almost always stretched and held tight during the processes of spinning and weaving, hence gaining a lot of internal stress. As the silk fibers are wetted, they act similarly to the overstretched rubber band, i.e., they naturally revert to the shrunken state. Therefore, the untreated silk has the potential for shrinkage of around 8% or even 10% without special care. If the silk is first made into a clothing item, then after one wash not only the sleeves will be shorter, but also the waist will be tight to an unnatural degree, and the overall shape will be ruined.

The concept of pre-shrinking is simply the act of having fabric properly shrunk down to its final size before it is cut and sewn into a finished product. The fabric will be shrunk down by using moisture(steam), controlled water temp. and/or controlled humidity conditions in conjunction with a specialty machine designed to shrink the fabric. Additionally, the amount of tension placed on the rollers while processing will be managed so that as much of the accumulated internal stress from being stretched while the fiber was being spun and woven will be released. This process is similar to giving the fabric a pre-heated water bath, which will cause the fabric to be in a properly sized state prior to cutting and sewing. Once the fabric has gone through this process the fiber structure will have stabilized and therefore all of the dimensional changes to the garment within a very narrow range after washing.

What happens if this process is omitted? For example, a silk nightgown might shrink from 45 inches to 42 inches after washing, resulting in a significant reduction in length and a tighter fit around the bust. The fabric itself might be a fine crepe de chine, but if the manufacturer skips pre-shrinking to save costs, the garment may look great at first but reveal its true shape after washing. Nine times out of ten, garment shrinkage problems stem from this process and have little to do with the inherent quality of the silk itself.

The lessons we learned have become our strict standards for material selection. Every roll of silk entering the warehouse must be randomly inspected; only those with a shrinkage rate consistently below 3% in both the horizontal and vertical directions are accepted. For fitted styles like dresses and shirts, this shrinkage must be reduced to below 2%. For some particularly size-sensitive patterns, the fabric is allowed to rest and shrink before cutting, or a light pre-shrinking process is performed after sewing, nipping any potential problems in the bud before shipping. These efforts are all done in unseen areas, increasing both time and cost, but they ensure that the difference between the "buyer's view" and the "seller's view" isn't just a matter of one wash.

Of course, even with excellent pre-shrinking, silk isn't indestructible. At the base, it is a protein fiber that can be affected by alkali and high temperatures. Hand washing with cold water using a neutral or silk detergent, very gently pressing (do not rubbing or wringing), then rolling out the remaining water with a large towel and laying flat to air dry these classic care habits are still the best basis for getting the same garment sizes time and again. Taking a hot tumble in the dryer is a no-no for pre-shrunk fabric as well.

Although the delivery journey is long and the package travels across oceans, the experience of opening it is almost everything. For us, pre-shrinking is an essential, cost-effective measure. It's invisible, but the comfort of clothes that still fit after several washes is something the user notices. Instead of wasting time explaining returns and responding to negative reviews, it's better to ensure the fabric "maintains its size" from the start. The next time you touch a smooth, draping silk shirt, the quiet, perfect fit is likely thanks to pre-shrinking.