There are four kinds of commercially grown cotton. Upland cotton is the most common and makes up 90% of the world’s cotton production. However, the most famous and luxurious kind of cotton is extra-long staple cotton such as Pima and Egyptian. Many countries around the world produce cotton, from the US to China to India and Australia.
Cotton Plants (the kind with leaves)
Cotton plants grow in tropical and subtropical climates. They’re planted in the spring and grow into shrubs about 1m (3-ish feet) high. Although cotton bolls are often mistaken for flowers, they’re actually the fruit of the cotton plant.
The cotton plant’s actual blossoms are beautiful. They’re yellow when they bloom, then turn pink, then red. The round fruit starts out green and turns brown as it matures, before finally bursting open to reveal the white fibres inside. The fluffy white boll holds the cotton seeds, just like an apple holds apple seeds. At harvest time, the cotton bolls are machine harvested and gathered into huge bales. They’re then sent to a cotton gin for processing.
Cotton Plants (the other kind)
At a processing plant (see what we did there?) or cotton gin, the baled cotton is mechanically loosened to remove leaves and seeds. The cotton tufts go through an initial cleaning before a carding machine combs through the fibres and aligns them, removing fine dust particles and short fibres. The resulting cotton is called sliver, a soft, loose strand of cotton fibres that resembles slightly fluffy rope. Some cotton is also combed, which removes even more of the impurities from the resulting yarn.
The next step in yarn production is drawing or drafting, in which fibres from the cotton sliver are passed through rollers. The rollers straighten and align the cotton fibres even more and produce roving—a thinner, firmer strand of uniform weight, ready for spinning. There are a number of ways to spin cotton yarn, but the most common method is ring spinning, in which roving is stretched with drawing rollers and then wound around a rotating spindle.
Note: it’s entirely possible to hand-spin cotton yarn. If you’re curious about it, we recommend this excellent blog post.
Why Cotton Yarn is Awesome
The cotton yarn you buy at a big box store is often not the softest, but not all cotton is created equal! Loosely spun 100% cotton yarn can be extremely soft, as can cotton-based blends. Extra-long staple cotton (like Pima and Egyptian) is known for its softness.
Cotton yarn isn’t only good for dishcloths! 100% cotton yarn is perfect for many household items including potholders, towels, rugs, and bags. It’s also great for warm-weather clothing such as light tops, cardigans, and tunics. A soft cotton yarn is perfect for baby clothes and blankets.
Lightweight and breathable
Cotton is a summer staple for a reason! It allows air to circulate around you and actively conducts heat away from your body.
Cotton can absorb a lot of water. That makes it handy for all kinds of household items but it also means that when you wear it, it keeps you cool by absorbing moisture when you sweat. It soaks up dyes well and is therefore available in a variety of intense colours.
Easy to launder
Cotton is generally machine washable (always follow a yarn’s specific care instructions) and, in fact, it gets softer the more you wash it. It can often be at least partially machine dried (no, seriously, please follow specific care instructions—we really can’t stress this enough!). It responds well to blocking, is generally iron-able (when not contraindicated by the instructions we keep telling you to check. Look, we’re willing to be obnoxious about this), and doesn’t pill. Cotton yarn is an excellent choice for baby clothing or blankets because it’s so easy to clean and care for.
Some Cons to Consider Re: Cotton
100% cotton yarn is not at all elastic. It may shrink a bit when washed, but it will also often stretch out when worn or worked with. This needs to be taken into consideration when you’re planning a project—you may want to use a smaller needle than a pattern calls for, and if you’re planning a large garment, you may want to consider a yarn that blends cotton with another fibre. Trailhead yarns offers a couple of beautiful cotton blends, including the Appalachian Trail base, which combines cotton and nylon for a truly versatile yarn.
Absorbent…but not moisture wicking
While cotton is absorbent, it does not, in fact, wick moisture away from the body. You’ll often be able to feel the wetness against your skin—which makes cotton great in warm weather but not at all ideal for winter activities.
Can be tricky to work with
Beginners may struggle with a 100% cotton yarn because of its lack of elasticity and the need to work with a tighter gauge. It’s entirely manageable with care, but it’s something to consider, especially if your hands get tired easily. A cotton blend can solve this issue for you if you want to use cotton but are concerned about hand fatigue (or any of the other cons on this list, really).
Dark colours may bleed
Although cotton yarn can absorb a large amount of vibrant dye, it can also be prone to bleeding, especially in a pattern where light and dark colours are placed side by side. You can check your pattern in advance by making a swatch with both colours together and then washing it to see how the colours interact.
Bleeding can be affected by many factors including the types of dye used and the methods of individual dyers, so it’s especially important to test with hand-dyed yarns, especially if the yarns in question aren’t machine washable.
Reputation for pesticides
Cotton is notorious for being a high-pesticide crop, and some cotton is certainly still grown with a reliance on pesticides. However, not all cotton is grown the same way. According to CottonAustralia.com, the use of pesticides on Australian cotton has been reduced by 97% since 1992.
Cotton farmers in the US have likewise been successful at IPM, or Integrated Pest Management, which involves using many tactics to control pests instead of relying solely on spraying.
Basically, if cotton is carefully sourced, pesticides are less of an issue than they were 20 years ago. Organic options also exist for consumers who want to ensure that their cotton yarn is 100% pesticide-free.