Hi, today I’m going to round out our fabric info blogs with a discussion about fibre content. Fibres are the raw materials from which fabrics are made. Each type of fibre has its own properties which in turn effect the properties of the fabric made from it and eventually the garment made from that fabric. So knowing a little about the different fibres and their properties is very important as a sewer.
Lots of fabrics are made by blending two or more fibres. This is done to add stretch, reduce cost and/or to reduce any negative properties of the fibres used. For example polyester and cotton are often blended for sheets because polyester is cheaper than cotton and doesn’t wrinkle whereas cotton ‘breathes’ so it is cooler and cotton also wicks or draws moisture away from the body. So theoretically by blending the two fibres you get cheaper sheets, that don’t wrinkle and that don’t make you sweaty at night.
Fibres fall into two basic groups-natural and man made. Within these groups they fall into several sub categories. Again, this is not an exhaustive list, just the most common fibres that you are like likely to see as sewers.
cellulose or plant based: cotton, linen, ramie, hemp, jute
protein or animal based: wool, silk
synthetic: polyester, nylon, acrylic, elastane (Lycra)
regenerated cellulose: viscose (rayon)
It is possible to identify a fibre by burning a little piece of the fabric. Be very careful and always just burn a tiny scrap either outside or over a sink. Let the fabric burn for a couple of seconds, extinguish the flames and then smell and observe the burnt fabric. If it’s a blended fabric you’ll be most likely to observe the qualities of the most dominant fibre. As I talk about each fibre type below I’ll describe what you’ll see and smell when you do a burn test.
Natural cellulose fibres
Cotton is the most commonly used fibre on the planet and is made from the ‘flowers’ or bolls of the cotton plant. I’m not going to go into the processes used to turn each raw material into yarn and then fabric in this blog as that would take far too long and probably bore you all stiff. But this is what cotton looks like on the plant.
By Ashish Wankhade Wankash at English Wikipedia (Ashish Wankhade Wankash at English Wikipedia) [Public domain], via Wikimedia Commons
Cotton has lots of great properties. It ‘breathes’ therefore is cool to wear, it’s quite strong but on the down side it does tend to shrink when washed. It has no natural lustre (shine), doesn’t drape particularly well and wrinkles easily.
When you burn cotton it will burn quickly and the ash left will be grey, soft and flakey. It will smell like burning paper.
Linen – The other common natural cellulose fibre we all know is linen. Linen comes from the flax plant. It is very strong, but can be a bit rough and it wrinkles a lot as anyone who owns a linen shirt will know. Like cotton, it breathes so is comfortable to wear.
linen burns in a similar way to cotton so you may need to use other ways to differentiate between the two such as linen feeling rougher than cotton.
Both linen and cotton fabrics are generally easy to sew so are good for beginners. Just remember to always pre-wash to shrink them before you start cutting out.
Natural protein fibres
Wool comes from sheep as we all know. It is an amazing fibre. Strong, cool to wear, fire retardant, wrinkle resistant and very versatile. It is used to make everything from carpet to babies under garments. It also has an amazing malleable quality which means it can be moulded with steam which makes it perfect for making suits.
When you burn wool it is slow to ignite and usually self extinguishes. The ash is black and flakey and there will be a strong smell of burning hair.
Silk – there’s nothing quite like silk. It’s lustre and handle are unique. However, it’s expensive, can be weak and hard to care for. Silk comes from the cocoon of the silk worm. The cocoons are dunked into boiling water killing the pupae inside(so you may want to consider if you’re ok with that before buying silk) and then the incredibly fine fibre is spun off the cocoon.
Cocoon of the silk worm. Bombyx mori Cocon 02″. Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Bombyx_mori_Cocon_02.jpg#/media/File:Bombyx_mori_Cocon_02.jpg
When you burn silk it will burn faster than wool, will have similar flakey ash when extinguished and the same burning hair smell as wool.
Man made fibres
Polyester is the most well known man made fibre. It’s made from oil and also can now be made from recycled plastics such as old soft drink bottles. This link is to a five minute vid on You Tube that shows the process from bottle to sweatshirt. It also shows an industrial knitting machine at work. http://youtu.be/zyF9MxlcItw.
Polyester is cheap and easy to care for. It rarely shrinks when washed. But it doesn’t breathe, so you’ll get hot and sweaty in polyester clothing. It also tends to attract oil based stains and can smell a bit when hot.
When polyester is burnt it burns quickly with black smoke and when extinguished you are left with black melted plastic like bead. It smells chemically.
Nylon and acrylic are very similar to polyester so I won’t go into detail about them.
Spandex biker by Ed Yourdon” by Ed Yourdon – http://www.flickr.com/photos/yourdon/3751395963/. Licensed under CC BY-SA 2.0 via Commons – https://commons.wikimedia.org/wiki/File:Spandex_biker_by_Ed_Yourdon.jpg#/media/File:Spandex_biker_by_Ed_Yourdon.jpg
Elastane is different from other fibres as it can’t be used to make fabric on its own. It is always blended in small quantities, usually up to 12%, with other fibres to add stretch and recovery to those fabrics. You may have noticed that I say elastane and then Lycra in brackets. That’s because elastane is the generic name for the stretchy fibre and Lycra is the brand name owned by Du Pont for their specific fibre. When you label a garment for sale you can only use the name ‘Lycra’ if you know for sure that the fibre used in your fabric is genuine Lycra from Du Pont, otherwise you have to call it elastane or spandex.
Elastane revolutionised swimwear and exercise wear when it was invented in the early 1960s. Suddenly it was possible to get a really tight fit that was comfortable to wear and didn’t sag when it got wet.
You can’t burn test for Lycra but if you give a small piece of fabric a good stretch and observe how far it stretches and how it recovers after stretching you should get a good idea if there is elastane in the fabric.
Man made regenerated
Viscose – 1950s it was discovered that fabrics would be made from waste cellulose such as wood pulp and cotton linters (the waste bits from the cotton plant). These are melted down using chemicals and extruded into fibres. The generic name for fabrics made from these fibres is viscose. You will often see the name rayon used as well this was an earlier name which has been replaced by the term viscose which covers a variety of fabrics such as cuprammonium and
Modal. You should pre-wash viscose before use as, like cotton, it can shrink.
When you burn viscose it is very similar to cotton so other ways you can tell you have viscose fabric is from the handle or feel of it. It sounds weird, but viscose feels soapy when you touch it. Plus it tends to drape better than cotton and can feel stiff when wet.
I hope you have found this three part super quick intro to fabrics useful. The best way to get your head around fabrics is to spend lots of time touching and looking at them. So next time you’re at the fabric shop look at and feel the fabrics, have a guess at whether they are knit or woven, what type of weave they have if woven, what fibres they are made from and finally what their common name is if they have one. also give burn testing a go (maybe not in the fabric shop 😀).
Next time I’m thinking that I’ll launch into pattern making with you. Maybe we should do a project like a simple skirt from start to finish. I’ll teach you how to measure correctly, draft a basic skirt block, adapt the block to make an A-line skirt. Then we can cut it out and sew it together. There are lots of elements such as making and applying your own bias binding, putting in an invisible zip and lining a garment that we can include in the skirt project. These can all be applied to other projects. So even if you don’t particularly want a skirt, the learning involved in the project will be super useful. Till next time. Kathy.