Thursday, September 16, 2010

All you ever wanted to know about wool and cloth diapering

On my forever quest for knowledge, I had the pleasure of interviewing Christine, owner of Knoodle Knits and Erin, owner of Wooltopia for this post. I hope you find them as informative as I did. If you have any questions don't hesitate to post a comment and I'll work on getting answers for you.

You may also want to view our post HERE on how to wash and lanolize your wool products.

Crunchy Babe (CB): What is Wool and how does it work for cloth diapering?

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.

CB: Why and how is it used in cloth diapering?

Wooltopia (W): Sheep make an oil on their skin called lanolin. When there is lanolin on the wool, the wool is very water resistant.  During the cleaning process most of the oil is washed out, but you can 'lanolize' your wool with a liquid lanolin.  However, wool is also naturally absorbent.  It can absorb up to 30% of it's own weight without feeling damp.  In addition, wool is naturally anti-microbial so when it soaks up urine it won't get a urine smell!

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.

CB: What are the different types of wool related to cloth diapering?

W: The wool typically used for cloth diapering comes from sheep.  They are many different types (i.e. merino, corridale, blue faced leiceister)  Each different type, or brand, will have different qualities.  Merino is extremely soft, but doesn't hold elasticity as well. 

KK: One of the other great advantages of using wool as a cloth diaper cover is that there are so many options available. First, let's look at the different manifestations of wool, including interlock, knit, and up-cycled products. Then, we'll discuss the different types of garments that can be made with these variations on the wool fiber.

Wool interlock is a knit fabric that comes in varying percentages of wool. For cloth diapering you want to find garments made from 100% wool interlock, or a 97% wool and 3% lycra blend (lycra adds some stretch to the wool). Since this type of wool behaves like fabric, it can be cut and sewn into a variety of different garments, and can take on the look of 'regular' clothes. 

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 from recycled sweaters. Old sweaters are cut and sewn, just like interlock, to produce a variety of wool garments. These covers can be made from any type of wool, including Cashmere. Sometimes, if the original sweater is too 'holey' or loosely knit, the garment is felted (purposely shocked by shrinking and and locking the fibers together irreversibly), then cut and sewn.
There are so many cute ways in which wool has been used to make cloth diaper covers. There are six basic garment choices available; longies, shorties, skirties, soakers....all of these items can be referred to as "woolies".


  1. Something to keep in mind is that merino is a pretty generic term. There are several bases popular for cloth diapering that are merino.. it's not the buttery soft yarn some are expecting. BBR is usually merino, though some of their blends have corriedale in it. There are so many variations, and milling processes that give each base it's individual textures and qualities. Most of the more common merino bases like BBR and CSF actually have wonderful stretch, which is a reason the base goes quite far in terms of pattern requirements. I would also describe the same two bases as not buttery soft, but still quite luxurious. Two top choices for people with toddlers. Though, from experience, bbr is not so much fun to knit. lol

  2. The Yarn Gnome~ If you'd like to elaborate on the questions I asked I'd be happy to add your answers in. Email me at CrunchyBabe "at"