Knitting Advice Nr. 9: Acrylic & co are not suitable for outer winter garments (wet plastic doesn’t keep you warm).

Polyester, acrylic and nylon are all petro-fibres, also known as plastics. And unlike wool, wet plastic doesn’t keep you warm. So why, oh why do some knitters spend time and money knitting outer winter garments (hats, beanies, headbands, mittens, gloves, scarves, and leg warmers) in acrylic and other petro-fibres? Because wet plastic is absolutely useless when wet. This choice only makes sense if you are intending to wear those items when it is not raining or snowing, or that you spend your wintertime between home, office, and car parks. If so, we can all agree that this acrylic-made outerwear is a reasonable option for you and your (possibly) very tight budget.

Wool is a natural wonder when it comes to insulating against the cold. Its intricate fibre structure creates tiny air pockets that trap heat and provide excellent insulation, making it ideal for staying warm in chilly weather. What sets wool apart from its petro-fibre ersatz is indeed its ability to wick moisture away from the body, keeping you warm even in wet conditions. In fact, wool’s moisture-wicking capacity is so effective that it’s the same natural mechanism that keeps animals warm in some of the most extreme weather conditions. Think yaks, Icelandic winters, sheep whose natural predators are arctic fox— you get the picture. You are wearing wool; you are wearing their fleece, taking advantage of its fantastic properties. Woollen items offer a cosy and breathable layer that adjusts to your body temperature and keeps you feeling snug and dry. Even when wet, wool retains some of its insulating properties. The air pockets in the wool fibres continue to trap heat and provide a degree of warmth. So, while your outerwear woollen items might get damp, wearing them will still keep you warmer than not wearing them.

Wet petro-fibre outer garments, on the contrary, feel clammy, uncomfortable, and—worst of all—cold. Once wet, petro-fibre outer garments (such as acrylic, polyester, and nylon) present a stark contrast to the warmth and comfort you’d expect. Petro-fibre materials, due to their synthetic origin, have a smooth and uniform structure that results in fewer air pockets within the fibres. These fibres are often round, compact, and lack the irregular spaces and voids found in natural fibres like wool. Consequently, when petro-fibre materials become wet, their ability to trap air and maintain warmth is compromised. The microscopic air pockets that typically create insulation are notably absent, causing these materials to feel cold and uncomfortable against the skin. Essentially, their lack of moisture absorption and their inability to retain heat when wet make them ill-suited for use in damp, rainy, or snowy weather. In short, if you’re wearing a damp outer garment made of petro-fibres, remove it ASAP, as wearing it will only lower your body temperature. Wet plastic doesn’t keep you warm. Wet wool does.

Now, let’s please all remember that acrylic outerwear items are 100% unsuitable for people who are living on the streets and at the receiving end of “charity knitting.” When choosing which charity you are knitting for, their policy regarding which fibre content they accept for which items might be a good indication of how serious the charity is regarding the welfare of their beneficiaries.

If I’ve managed to convince you of the importance of choosing real wool for outwear winter knits, you might be wondering if, despite a tight budget, you can find affordable wool. My answer is : yes, there are options available. While I don’t know much about US wool brands, I’ve noticed that even Walmart carries 100% wool skeins. In Central Europe, where Aldi and Lidl are common, I’ve had less than ideal experiences with their wool, so I don’t feel comfortable recommend it. Instead, I’d suggest exploring online options like Hobbii, where you can find their budget-friendly ‘Friends’ brand. I haven’t tried their 100% wool skeins yet, but I’ve had a positive experience with their cotton, which was easy to knit with and didn’t split. In my opinion, Sandnes Garn is another viable option with competitive prices (you can order their wool from Rascol). For further guidance on where to find budget-friendly yarn, you might want to visit Charity Knitting. Nicole has an insightful post on about 14 Sites Where You Can Save Big on Quality Yarn,’ and it’s worth mentioning that she also recommend Hobbii as a good choice. Her post includes additional tips for sourcing affordable wool in Australia, the US, the UK, and the European Union.
I must stress that I don’t claim to be an expert in sourcing cheap wool. My recommendations in this post are based on my (limited) personal experience in the matter. I haven’t received any payment or incentives from the brands mentioned. So it’s at least an independent opinion, if not the result of an extensive research and experience. What I do feel a 100% confident about, and that will be my conclusion : “For winter outerwear, cheap 100% wool yarn is better than any petro-fibre yarn, even ones at the higher price tag range“.

As a quick side note, I plan to give Hobbii’s affordable 100% wool from their ‘Friends’ brand a try. In fact, I am even going to knit an entire sweater with this wool in order to assess if this wool is easy to work with or not, whether it’s prone to splitting or pilling, if the wool was well spun (or if the skeins come knots included – yes, this does happen with some cheap yarn!), etc. However, I won’t be able to embark on this experiment until February-March because, at the moment, I’m doing by best to try and finish my swatches for the TKGA Level 1 certification.