You may also want to view our post HERE on how to wash and lanolize your wool products.
Knoodle Knits (K): Wool is a natural protein fiber that comes from sheep. If you look at it under a microscope, you will see that it is covered by interlocking scales (the cuticle). This structure, combined with the sebaceous grease that coats the fiber as it emerges from the follicle (lanolin), is what makes wool water repellent. However, water repellency is only one of the reasons that wool is used for cloth diaper covers.
Wool is all natural, whereas PUL is synthetic. Wool is breathable, whereas PUL is more plasticy and holds the moisture in. Wool won't delaminate or wear over time in the same way as a PUL diaper. PUL needs to be washed after each use whereas wool only needs to be washed every 2-3 weeks!
KK: Aside from water repellency, there are several other factors that contribute to the success of wool as a cloth diaper cover.
Wool is environmentally sustainable. If you are cloth diapering you are already contributing to global change. But did you know that using wool products supports local farmers throughout the world? Most wool is produced organically or with low use of harmful chemicals. The processing of wool requires very little environmental impact compared to other natural fibers or man-made fibers. And, wool can be reused multiple times, and even up-cycled when it is no longer needed for it's original purpose.
Wool breathes, meaning it is hygroscopic; able to absorb and release moisture as needed. In fact, most wool fiber can absorb up to three times its weight in moisture. That moisture then evaporates back into the air. This evaporative process gives wool a natural cooling and heating system, keeping sheep (and humans) warm and dry. When used as a cloth diaper cover, it wicks moisture away from your baby's skin. Keeping baby's bottom dry is key to preventing diaper rash. It is the reason why you CAN use wool in the the summer months. It is also the reason why wool is a better choice than PUL, for cloth diaper covers. PUL (polyurethane laminated fabric) is basically plastic backed fabric. While PUL is waterproof and can be autoclaved (sterilized in extreme heat), it does have a few drawbacks. PUL is designed to trap moisture and prevent it from leaking. Since PUL does not wick, moisture stays trapped against baby's skin, which can lead to irritation and rashes. PUL also traps heat in the same fashion that a disposable diaper does. It does not have the same temperature regulating properties of wool, therefore in the summer months a child can become warm from wearing a PUL cover versus a wool cover. Finally, PUL is not biodegradable. The process for manufacturing PUL covers is not environmentally friendly (it's actually quite toxic), and relies on the availability of our already taxed petroleum resources.
Wool is very poor at conducting static electricity, therefore, it is the least likely fiber to attract dirt and dust. Even dust mites hate wool. This is great for allergy sufferers, or those with sensitive skin. In fact, if someone is allergic to wool, it is likely not so much an allergy, as it is a hypersensitivity to the texture of the scales scratching on a person's skin.
Wool is naturally antibacterial, anti-fungal and antimicrobial. Wool inhibits the growth of microbes because those things tend to be attracted to smooth, positively charged surfaces, like those of synthetic fibers, rather than the scaly, neutrally charged surface of wool. This means that even with heavy use, wool diaper covers usually do not have ammonia build up, or other bodily odors, as they are both caused by bacterial growth. Wool will not trap and retain odors from outside sources either (pets, smoke, food), a simple 'airing out' is all that is needed. Finally, frequent washes are not necessary. Unless the garment is soiled (poop), stained, or has gone through several soaking wet diapers, you can simply leave it out to dry for a few hours.
Finally, wool is flame and fire resistant. The wool fibers are structured in such a way that if exposed to flame, they will smolder and try to extinguish themselves. Which is why wool is used to make fire blankets, rugs, curtains, bedding, mattresses, and other upholstery. This also makes it a great choice for infant and children's clothing.
Knit garments are produced by knitting or crocheting wool yarn. It is important to use 100% wool yarn when making cloth diaper covers, as synthetic fibers can inhibit the very properties that make wool so successful. There are several different types of wool yarn; Merino, Cormo, Rabouillet, Cestari, Corriedale, Blue Faced Leicester, to name a few. What you use can be a matter of personal preference, although some are softer, some are more sturdy, and others have more of a luster and take dye well. You can also choose to use mass-manufactured wool or small production hand-dyed, hand spun wool.
Up-cycled products are cloth diaper covers made