Why Cashmere Pills and What You Can Actually Do About It

Pilling on cashmere garments is the result of fundamental textile physics, not necessarily an indicator of poor quality. The phenomenon occurs when short or loose fibers migrate to the surface of the fabric, where friction from wear causes them to entangle into small nodules, or "pills." The degree of pilling is primarily determined by the length and diameter of the cashmere fibers used in the yarn, as well as the construction of the yarn and the garment itself. While all cashmere is prone to some pilling, higher-grade cashmere with longer, finer fibers will pill significantly less and stabilize after the initial period of wear.

The Physics of Pilling: A Microscopic View

Pilling is a three-stage process: fuzz formation, entanglement, and pill growth. It begins when the mechanical action of wearing a garment causes individual fibers to loosen and protrude from the yarn structure. These loose fibers form a layer of fuzz on the fabric surface. With continued friction, these fibers then tangle together. The entanglement tightens and gathers more loose fibers, forming a dense, spherical pill that is anchored to the fabric by a few remaining fibers. The tendency of a fiber to pill is related to its properties. Shorter fibers, for instance, are more likely to protrude from the yarn and form pills. This is why a garment made from high-quality, long-staple cashmere (with fibers of 34-36mm) will be more resistant to pilling than one made from shorter, lower-quality fibers.

The severity of pilling is also influenced by the type of friction the garment is exposed to. Rubbing friction, which occurs when the fabric rubs against another surface (such as a seatbelt or the strap of a bag), is the most common cause of pilling. Flexural friction, which occurs when the fabric is bent or folded, can also contribute to pilling, particularly in areas such as the elbows and knees. The intensity and duration of the friction also play a role. A garment that is worn frequently and subjected to high levels of friction will pill more quickly than one that is worn less often.

Deconstructing Cashmere Quality: Fiber Length, Diameter, and Dehairing

The quality of a cashmere garment is a direct function of the raw material. The finest cashmere fibers are harvested from the undercoat of the Capra hircus laniger goat, which produces a fleece of exceptionally fine, soft fibers as insulation against the harsh climates of its native regions. To be legally classified as cashmere, the average fiber diameter must not exceed 19 microns. Premium cashmere, often referred to as Grade A, has a diameter of around 14 to 15.5 microns. However, fiber diameter alone is not the sole determinant of quality. Fiber length is equally critical. Longer fibers can be spun into stronger, more stable yarns with fewer exposed ends, which directly translates to a lower propensity for pilling. The process of dehairing, which separates the soft undercoat from the coarse outer guard hairs, is also crucial. Incomplete dehairing leaves coarse fibers in the yarn, which can cause prickliness and are more prone to pilling.

The world's most prized cashmere comes from Inner Mongolia, a region known for its extreme temperatures. The goats in this region produce a fleece with an average fiber diameter of 14.5 microns and a length of 34-36mm. In contrast, cashmere from other regions may have a larger diameter and shorter length, resulting in a garment that is less soft and more prone to pilling. The dehairing process is a meticulous and labor-intensive one. The raw fleece is first sorted by hand to remove any large impurities. It is then washed and dehaired, a process that can be done either mechanically or by hand. Hand-dehairing is the traditional method and is still considered to be the best way to preserve the length and integrity of the fibers.

The Role of Yarn Construction and Knitwear Finishing

The way cashmere fibers are spun into yarn significantly influences the final garment's performance. There are two primary spinning systems: worsted and woolen. Worsted-spun yarns are made from longer, combed fibers that are aligned in parallel before spinning. This creates a smooth, strong, and dense yarn that is less likely to pill. Woolen-spun yarns, on the other hand, use a mix of shorter and longer fibers that are not combed, resulting in a loftier, fuzzier yarn with more protruding fiber ends. While woolen-spun yarns can feel exceptionally soft initially, they are inherently more susceptible to pilling. The finishing process can also impact pilling. Aggressive brushing or chemical treatments can be used to create a deceptively soft and lofty surface, but this process can also weaken the fibers and increase the likelihood of pilling over time.

The ply of the yarn also plays a role in pilling. A 2-ply yarn, which is made by twisting two single strands of yarn together, is stronger and more durable than a single-ply yarn. The twisting process helps to lock in the fibers and prevent them from migrating to the surface. As a result, a garment made from a 2-ply yarn will be less prone to pilling than one made from a single-ply yarn. The knit structure of the garment can also affect pilling. A tightly knit garment will be more resistant to pilling than a loosely knit one, as the fibers are held more securely in place.

A Practical Guide to Minimizing and Managing Pilling

While pilling cannot be entirely prevented, its occurrence can be minimized through proper care. Hand washing in cold water (30°C) with a pH-neutral detergent is the recommended method for cleaning cashmere. Avoid twisting or wringing the garment; instead, gently squeeze out excess water. To dry, lay the garment flat on a towel, away from direct heat or sunlight. Hanging a wet cashmere garment can cause it to stretch and lose its shape. When pills do appear, they can be removed with a cashmere comb or a fabric shaver. Lay the garment on a flat surface and gently glide the comb over the affected areas in one direction. It is important to note that after the initial few wears and de-pilling sessions, a high-quality cashmere garment will stabilize, and pilling will significantly decrease as the shorter fibers are shed. For more information on our materials, please visit our materials page.

When storing your cashmere garments, it is best to fold them and place them in a breathable garment bag. This will protect them from dust and moths, while also allowing air to circulate. Avoid storing your cashmere in plastic bags, as this can trap moisture and lead to mildew. If you are storing your cashmere for an extended period of time, it is a good idea to add some cedar balls or lavender sachets to the bag to help repel moths.

Frequently Asked Questions

Is pilling a sign of low-quality cashmere?

Not necessarily. All cashmere will pill to some extent, especially when new. However, excessive or persistent pilling is often an indication of shorter fiber length, poor yarn construction, or overly aggressive finishing techniques, which are characteristic of lower-quality cashmere.

Can I stop my cashmere from pilling completely?

It is not possible to completely stop cashmere from pilling, as it is a natural characteristic of the fiber. However, by choosing high-quality cashmere and following proper care instructions, you can significantly minimize pilling and maintain the appearance of your garment.

What is the best tool for removing pills?

A cashmere comb is the most effective and gentle tool for removing pills from cashmere. A fabric shaver can also be used, but it is more aggressive and should be used with caution to avoid damaging the garment.

How often should I de-pill my cashmere?

You should de-pill your cashmere as needed, whenever you notice pills forming. However, it is important to be gentle and not to overdo it, as this can damage the fibers. After the initial few wears, you will likely find that you need to de-pill your garment less frequently.