Let's see if I can talk about these wonderful fibers and not bore you too much because they are so cool in a geeky, science-y sort of way!
Rayon is perhaps one of the least understood fibers worked with by hand crafters. Rayon came into existence in the attempt for humans to duplicate what a silk worm does naturally. That is, turn plant material into a fine, highly desirable fiber. In essence, rayon is artificial silk.
Many people erroneously think that rayon is a synthetic fiber but it is not; it is a cellulose fiber. While it is man-made, the raw material is from plant material, most frequently wood pulp. You may recall from high school science class that the cell walls of plants are made from cellulose. Using various chemical methods the cells are broken down and reconstructed then forced through spinnerets (tiny holes) to create rayon fibers which are then spun into threads and yarns. Because rayon is a cellulose fiber, it can be considered renewable. It is also biodegradable, and it can be dyed in brilliant colors using the same kinds of dye used to dye cotton and linen or by incorporating dye into it during processing. Some processes for making rayon can be fairly water intensive and can use varying quantities of chemicals but overall it is much more environmentally friendly than synthetics made from petroleum-based products.
There are several different kinds of rayon each using different variations of plant materials and chemical processes.
Viscose is probably the most common form of rayon; it's sometimes just called viscose or viscose rayon. It is a very soft fiber that feels good next to the skin. It has beautiful drape, very much like silk but not as elastic. It is highly absorbent but does become weaker when wet so can lose resiliency if wet blocked too hard. So only block hard if you want more drape and less "bounce" in your finished garment. Rayon is washable. Most garment labels will specify if you should wash or dry clean. If the label says to dry clean you should do so, as some rayon is not as colorfast and the dye will run unevenly. Ask me how I know! I'll show you the lovely rayon scarves I purchased back in the 80's and how they look rather tie dyed now. If you should want to take the chance and wash a rayon item that specifies dry clean only, test an inconspicuous area to check for colorfastness.
We have many yarns that contain rayon/viscose. My personal favorites are Classic Elite Firefly, Plymouth Linen Concerto, Crystal Palace Monaco (which is on sale!), Berroco Lago, and Rowan Panama.
I encourage you to use our Advanced yarn search to find other rayon and viscose yarns and our Advanced Fabric search to find rayon fabric and ribbons!
Modal is a type of rayon made from European Beech trees which are grown specifically as a renewable resource. Modal is the registered trademark for Lenzing AG in Austria. The process of making Modal reportedly uses less water and fewer chemicals than other types of rayon. It is my understanding that all of the chemicals used to make Modal are completely recaptured and reused. Modal is very smooth, soft and about 50% more absorbent than mercerized cotton. Elsebeth Lavold Hempathy is one yarn that contains Modal along with cotton and hemp.
Tencel is another trademarked name for another type of rayon, lyocell. This fiber is extremely drapey, doesn't wrinkle easily, absorbs dye well and has a lovely sheen. There are a quite a few lines of travel clothing made from Tencel. At the moment we don't have any Tencel yarns but watch for new ones and know they are a delight to work with!
Soysilk, the registered trademark of South West Trading Company for a type of rayon made from soybean pulp that is left after pressing the beans to remove the oil. Unlike the other types of rayon which help you feel cool in warmer weather, soysilk feels warm but does wick moisture away from the skin as do other rayons.
Seacell, is the trademarked name of a type of lyocell that has about 5% seaweed added to the base materials. It is said that the natural minerals found in the seaweed are retained in the yarn and could possibly be imparted to the skin, contributing desirable minerals to help keep your skin healthy. Hand Maiden Sea Silk is the only yarn we have with seacell.
Bamboo is another rayon that is from a highly renewable resource and has the unusual property of being antibacterial even after many washings. Bamboo fiber is very soft and absorbs moisture very quickly then allows it to evaporate just as quickly so it helps you to remain very comfortable. It makes excellent bath towels and sheets. Yarn containing bamboo will have a nice soft drape, excellent wicking ability and dyes in beautifully vibrant colors. It is an excellent fiber for making warm weather socks! It's also great for shells, tops, coverups, evening wear, hand towels, baby clothes or any time you want a cooler fabric with drape, shine, durability and the added bonus of being renewable. Some of my favorite bamboo yarns are: Be Sweet Bamboo & Bambino, Crystal Palace Panda Silk, Classic Elite Wool Bam Boo, Vail, Chalet, HiKoo CoBaSi, Frog Tree Pediboo Sock & Worsted, and Univeral Bamboo Pop.
Corn and other high starch agricultural products like sugar & wheat are also being broken down through chemical processes to form polymers, which are then spun into fibers! We are currently out of any yarns that contain corn but do watch for Araucania Ruca which is 100% sugar viscose. We'll be getting more in a few weeks!
Acetate is a slightly different type of fiber that starts with wood pulp but goes through a different chemical process. It has been around for decades, and most of us are familiar with the shiny fabric that melts when ironed too hot.
Last, but far from least, is one of the newer technologies, Outlast viscose! According to the Outlast website (in geek speak): it is a phase change material that can be incorporated into or coated on a fiber and adapts to the temperature of your body. It pulls excess warmth away or radiates warmth back depending on what is needed. I recommend visiting the website, Outlast.com, to find out the more technical aspects, which are really cool if, like me, you love geeky science stuff but I fear will put many people to sleep. So far, the only yarns I know of that incorporate this high tech fiber are Lorna's Laces Sportmate & Solemate!
Are you still with me? I didn't put you to sleep with too many facts? Good! Rayon is one of my very favorite fibers to wear. I have several knitting project planned with these awesome yarns like Paseo in Lorna's Laces Solemate and Cocoknits Belle in Classic Elite Firefly. I'm very much looking forward to learning to sew better so I can try some fabrics too!
I hope this helps clear up some confusions about these wonderful fibers! There is lots more to read about each of them if you're interested. Check out The Knitter's Book of Yarn which has been very helpful to me in preparing this post for you and then don't forget to search the web!
If I can help further please drop me an email: askTerry (at) jimmybeanswool (dot) com.
Happy Knitting, Crocheting and Sewing!
Terry