Monday, November 7, 2011

A felting primer for hand knits (wet felting)

Felting knitting, or "what's in a name?"
Some call it fulling, and that's probably the most technically correct. Some call it "boiled wool," and you can certainly boil it, but you don't have to. I think most people call it felting, so I will too.

So, what IS felting?
This post is about wet felting.  Wet felting happens when wool is subjected to three factors simultaneously.  First, there must be WETTING; second, TEMPERATURE CHANGE and third, AGITATION.  When all three of these things happen at once, woolen fabric will shrink substantially, becoming both thicker and smaller. (There is another kind of felting done dry which is worked with barbed needles.  This is called needle felting, but it is not covered in today's post.)

Why felt?
Felting has two sides to its nature: the utility aspect, and beauty inherent in such a dense fabric.
Felt is as close to a miracle fiber as you can make outside of a lab.  It is somewhat rain-proof, somewhat wind-proof, immensely warm and very hard-wearing--nomads in some of the world's coldest places live in felt hutsdress themselves in felted hats and shoes and use felt saddle cloths on their horses. Closer to home, my kids have worn felted mittens here in Wisconsin for years: here is the same pair as shown in the opening illustration after they were worn for two years by a little boy for snowball fights, sledding and all-around tom-foolery.  An unfelted mitten would never have survived, but these are tucked away safe, waiting for another little kid who needs bomb-proof mittens.

< threadjack >
If you want to make the mittens illustrated in this post, they are available in a couple of ways:
For recipe (free)  click here
For the pattern ($3.25, child's XS-XL) you can
*Click through to the pattern page
*Click through to the project page 
*or buy the pattern now

<  / threadjack >
beauty of the fabric
However, utility knits aren't the only reason to felt.  Felting is inherent beautiful with a soft, lush look.  The stitches lose definition and meld together, the surface becomes matte. Here is a peek at the fabric of a felted cushion.  The density of the fabric not only makes it wear hard, but makes it almost luminous--the depth of the fabric reacts with light differently than a thinner or smoother or shinier fabric would, the colors seem more saturated.  Of all the cushions we have in the house, this is the one that people find themselves holding and carrying around from place to place.

Felting is irreversible
Felting is an irreversible process.  Once felted, a hand knit garment cannot be unraveled. The yarn has stuck to itself and congealed into a solid mass. This irreversibility has both downside and upside.
  • On the downside, that beautiful hand knit which went into the washing machine by accident has been ruined, yes.  Nothing--not vinegar, not yogurt, not shampoo, not conditioner--can bring it back to its pre-felted state.  
  • On the upside, it is the very irreversibility of the process that makes felted items so hard-wearing. Felted knitting can be cut, sewn and shaped. It will not unravel, so a felted sweater can have a long and lovely second act cut up and sewn into cozy mittens and slippers. 

Felting is unpredictable
Besides being irreversible, felting is also unpredictable.  Sometimes, felting occurs gradually and evenly across an entire garment.  More often, the process occurs suddenly and unevenly. Accordingly, felting garments to fit is something of a gamble. It is true that felted garments are available for sale--"boiled wool" jackets are a famous example. However, these garments are made from sheets of knitting which has been felted and then cut and sewn.  The jackets are not "boiled," the fabric is. For this reason, most knit-and-felt patterns are for bags, or mittens, or slippers: items where the fit isn't super-important.

Four ways to felt
The two main ways to felt are by hand, or using a washing machine.  Two other methods are by using a (clean!) toilet-plunger or by using a dryer. Whichever way you choose, however, consider turning the item inside out first, because the exposed side can get a bit roughed up by the process.

With hand-felting, you have more control over the project.  The mittens in the photo above were stopped from felting further at just the right time by having a paper pattern handy, against which the mittens were frequently compared as the size got nearer and nearer.

For larger projects, or for projects where fit is not so much of an issue, felting in the washing machine is a good choice.  Felting a large project by hand makes you realize the immense strength that the old washer-women must have had, to wrestle wet and heavy fabrics by hand.

hand felting
The basis of felting is that you knead and rub with the aid of dish-washing detergent—the suds act as a lubricant, making the rubbing easier.  (That's hand dishwashing detergent, not machine detergent!)

First, prepare a basin with cold water, and another with hot water, as hot as you can stand.  (Hint: wearing dishwashing gloves lets you use far hotter water than you could stand without them.) Wet the item to be felted in the hot water, then lift it out of the water and rub and knead a drop or two of dish detergent through it.  Hold one part of the item in one hand and the other part in the other hand, and rub the item on itself, changing your grip frequently to bring new parts into the process. Rubbing evenly all over gets the best all-over felting. 

Dunk the item into the hot water again, and begin to wash the detergent out, then abruptly dunk the item in the cold water and continue kneading and rubbing.  Again lift the item out of the water, add a drop or two of detergent, then agitate and rub for a while. Continue in the manner, alternating sudsy kneading under hot and cold shocks until the item is the size you want. The felting and shrinking usually occurs when the cold water shocks the wool, although it sometimes occurs on a hot-water shock.

Sometimes glove fingers or mitten thumbs fingers might try and felt shut.  Keep a wooden-spoon handle or chopstick handy to poke apart unwanted interior felting.

If you want to try boiling, dunk the project into a pot of boiling water , stir it with a wooden spoon, dunk it back in the cold water and do the soap and agitation cold.  Repeat. One thing about boiling is that dyes used on woolens aren't always benign. Be sure to wash the pot very thoroughly afterwards, and use only a stainless steel pot to avoid unwanted interaction of the pot-metal with the dyes. 

However you do it, this process sometimes takes a LOT longer than you think, and you might have to replace the hot water with fresh if it gets too cool.  Depending on the color and type of wool, it has taken me as long as 20 minutes of constant agitation and temperature shocks to felt one measly mitten.  Other times, however, the process takes place so fast you can hardly see it happening.  If it is taking a while, take heart: although you may doubt it while you are wrestling away, as long as the item was knit with ordinary wool (NOT SUPERWASH!!!) it will eventually shrink. 

When the item is the size you want, stop rubbing.  Let the item come to room temperature, then gently rinse out the suds in fresh lukewarm water, then lay flat to dry out of the sun. 

washing machine felting: 
top loaders vs. front loaders
The easiest machine for felting in an old-fashioned top loader you can stop in mid cycle. This lets you haul out the wet item to test the size as the process progresses.  These old top-loaders also let you re-position stuff--sometimes items to be felted get folded on themselves during the spin cycle, and the marks left behind can be hard to get rid of. Another advantage is that, on most top-loaders, you can change the cycle with the twist of a dial, easily switching from wash to rinse to spin. Yet another advantage is that you can keep cleaning the lint screen if your project sheds. Top loaders do have one important downside, though: believe it or not, a washing machine agitator can break your arm. Be sure the machine is turned OFF before you reach in. 

Felting can also be done with a front-loader.  These machines lock and it is often difficult to change the pre-set program once its started, so to get around this, choose the shortest cycle. This lets you keep checking the size after each run-through.

machine how-to
The principles of felting are the same whether by hand or machine: lots of temperature changes, lots of agitation. Each machine has different settings, so look for a heavy-duty cycle (lots of agitation) with abrupt temperature changes (hot wash followed by cold rinse, or vice versa).  Unless the item is massive, it probably makes more sense to toss your felting in with a compatible load (or loads!) you were planning to run anyway. 

Some people prefer to run the item through the washer in a mesh bag or a pillow case. This does help catch the fibers from the wool, but has the downside that the fibers may be re-deposited on the surface of the item. Nevertheless, if your machine is elderly or likely to get clogged from a particularly wooly project, a bag is probably a good idea. 

If you are using a method where you can't get at the item during the felting process (the item is in a pillow case or a mesh bag, or if you are using a front loader which can't be stopped) you might want to consider stuffing the project loosely with a small rag.  This helps keep the item from folding over on itself inside the bag or during the spin cycle: folding can leave crease marks. For small items, a loose stuffing can also help prevent the item from starting to felt to itself.

Yet another trick: a toilet plunger
A toilet plunger offers yet another way to felt.  Yes, this sounds d.i.s.g.u.s.t.i.n.g, and so it would be if you used the same plunger for felting as for your toilet.  Yuk.  Don't do that. Buy a brand new toilet plunger and hide it away when you're not felting.

Fill the tub with hot water, and the bathroom sink with cold water and have at it with the plunger. This is more work that machine felting but less work than hand-felting.  Plus, unlike front-loader felting, with a toilet plunger, you can stop at any time to check the project. 

A final trick: dryer felting
You can also felt hand knits, sort of, in a dryer.  You put in the wet item (turn it inside out) and the dryer does the temperature change and agitation part.  The upside of this is that you can stop the dryer at any time and have a look, the downside is that it often takes multiple wetting/drying cycles to get a moderate amount of felting:  the temperature change is gradual, and the agitation less than if the item were in water. This will eventually work, but it's slow, and even slower if you put it into a bag or pillow case. 

Washing felted items
Just because something is felted doesn't mean it won't shrink if you wash it again.  The upside is that if the item is still too big, you can re-felt it.  But if you'd like the felted item to retain its size, wash it the same way you would wash all woolens: cool water, no agitation, no temperature shocks, and no dryer. On the other hand, felt doesn't really seem to get very dirty--to my recollection, I've never actually had to wash a pair of felted mittens.

There is something about felted wool which pairs well with embroidery.  Below are some "alien eyeball" mittens (also much worn) which were embroidered after felting with a sharp needle and woolen (called "tapestry") yarn.  Although there are exceptions, knitting generally doesn't play well with embroidery because the embroidery sinks into the stitches.  However, felted knitting has no such problem. 

(These are child's size large from the kid-mitt pattern, just somewhat misshapen, you know, from long wear.)

--Good knitting, TK
You have been reading TECHknitting on "felting knitting." 


Martha Joy said...

I want to add a method of hand-felting that is easier on the muscles than what you described here.

Use a bamboo mat, like the ones for making sushi. You can get them in larger sizes too, as placemats for tables, and a weird kind of curtains. (I'm sorry, English is not my native language, and I'm not even sure what the word is in Norwegian. My grandmother used them to shade her potted plants in summer. Made from some kind of white wood in thin strips, held together by cotton string.)

What you do is place a towel on a table, place the mat on top, and then lay your woolen project on top of that. Wet through with soapy water. Roll the project and mat together, roll the towel around that. Or roll all three together. Now, to felt, you roll gently, gently in the beginning, for maybe two or five minutes. Just to get the felting started. Unwrap from time to time to check your progress. When the felting has caught on, you can start rolling much harder and use more force. This will speed up the felting, so check progress again!

It's important to turn you project 90 degrees from time to time, because this method will felt more in the direction you're rolling. Also, if I remember correctly, the inner end of your roll is felted a little more than the outer, but I'm not 100% positive on that.

The towel is not strictly necessary for the felting, it's there to soak up water. You should add more soapy water while you work. It's not necessary to change temperature, the manipulation of the rolling mat will do it alone. I'd use lukewarm water, because that's the most comfortable. It will cool while you work, of course.

This method works for both loose wool, to make hats, scarves, bags, etc, and for knitted items. When I learned it, it was with loose wool, making pictures. Like a kind of woolen painting :)

Trikada said...

Kiel bela gxi estas.

Sarah {The Student Knitter} said...

Nicely done! This was a super informative post. I've so far avoided felting as I really enjoy the individual stitches and I would be so hurt if something I knitted got ruined in the felting process. But I do like the way colourwork bleeds together when felted.... so maybe I'll have to give it a whirl :)

Suzanne said...

Wow, I can't believe how much you covered in this post. I learned A LOT!

Melissa said...

I would love to have the recipe for these mittens, but the link for it takes me to another blog post. Is there a particular book or other place that I can find a recipe for felted mittens?


TECHknitter said...

Hi Melissa-that other blog post IS the recipe--in other words, just the basics for how to make these kinds of mitten and the kinds of yarns to use. You can adapt that idea using a pattern you might have on hand. Best, TK

TECHknitter said...

Hi Martha Joy: Have you (or any other reader) used this method on a garment? It seems ideal for flat sheets of wool, like the pictures you describe, but would it make a two-layer object, like a knitted garment, felt together? Thanks for this fascinating explanation. TK

kmkat said...

Thanks for the education! I have done some felting (always intentional so far, knock on wood) and learned a number of things here. Stuffing the inside with a rag to prevent the object from felting shut -- I will definitely use that.

Pulsatorius said...

Luckily for me it is quite clear what to say in Swedish. "Filtning" is what happens to the fabric and "tovning" is performed on lose fibres and "valkning" is performed on fabric, weaved or knitted.
I use the built in wash-board in the wash-basin to felt my knitted objects. The built in wash-board might be a Swedish feature.
The temperature shocking is new to me. I believe that it is the high temperature with agitation, and the alkaline solution e.g. soft soap that makes the wool fibre felt. I have newer temperature shocked the wool to make it felt. I just continue at the high temperature until the felting is finished and then stop the process with some cold acidic solution to neutralise the alkali e.g. some vinegar essence in the first rinse water. Then I rinse with cold water.

Daisy said...

These are lovely. While I know my kids would love them, I confess to wanting a grown-up pair of my own, too. Any plans to expand the size range?

TECHknitter said...

Hi Diasy--I have actually worked these out for adults (men and women) in a slightly different pattern which has an internal cuff and an over-gauntlet. Until you wrote, I had almost forgotten about that. Maybe if there is some more interest expressed, I will plunge around my project room and knitting notebooks and put all that together. Thanks for writing, TK

Kathy W. said...

Actually, detergent is used in felting to raise the pH, which assists in the felting process. I usually make a gel with soap for hand felting, and if needed, add some Murphy's Oil Soap and/or baking soda to further elevate the pH, depending on the type of wool I am felting. The soap/detergent needs to be completely rinsed from the felted item, and a vinegar rinse helps return the pH to normal for wool.

Hannah said...

Thanks for the post! I am definitely inspired to make some felted mittens of my own now.

One thing, though - ordinary knitting can be embroidered, but I suspect fine, tightly knit fabric works better that looser knits for this purpose. For some examples, check out Lene's blog,Dances With Wool. I often admire her work.

TECHknitter said...

Hannah--you are right! I had forgotten about Lene's beautiful work. I think you are right that the knits are tight, and on small needles, but boy, that is beautiful embroidery. I will amend the text to reflect. Best, TK

Martha Joy said...

Yes, I guess it's better for one layer projects. But I have used this technique for a hat and a pair of socks too. You just cut a plastic bag and put inside. For the hat I think we had linoleum, I did that one in school 15 years ago, so I'm not quite sure. That was made from unspun wool, not a knitted project at all. I think I would use several pieces of plastic, in decreasing sizes to make sure I didn't felt mittens and such together. But since you felt by hand, you have control over the outcome and can stop to open up your project while working. I'd still recommend plastic in-between. Tell us if you try it out!

Tiddy and Charlie. said...

What a great idea :o) c x

random Cindy said...

Great post! I can felt by hand in the sink okay, but I have had little success with the washer and I have a very ordinary top loader. Throwing pieces in with the regular wash seems to reduce the amount of agitation they get. I'll have to work on that more. I can't even seem to felt wool yardage.

I have done something similar to Martha Joy's method except I used the plastic floor matting with ridges on it. (Brand new and clean!) I used two pieces, one on top and bottom with a plastic bag inside the hat so it wouldn't felt to itself. I did alternate temperatures and did the whole thing in a clean sink.
I think the method would work in the bathtub or even outside for a larger object.

Angela said...

GREAT post. Really informative. No wonder that stranded swatch I threw in with a load of wash didn't felt evenly.

caitcreates said...

I haven't done a lot of felting, so my question may be one that is quite obvious to more veteran felters:

Is the ribbing on your mittens felted? If not, how do you felt the hand part of the mittens without felting the wrist part? I would think that the ribbing would lose elasticity if it were felted.

TECHknitter said...

Hi Caitcreates. The ribbing does not felt because it is made of non-felting wool (superwash). Here is a link (cut and paste into your browser window) which has more information.

Best, TK

Eric Tischler said...

Great post.

I would like to add that if your piece does not felt evenly that you can shape it some with a trick I learned reading about making felted hats. The fabric will shrink in line with the direction you are rubbing it, so if you have a part that is too wide, or a corner that is out of bounds, rub back and forth in line with the area that needs to be shrunk more. It will pull in.

Another tip: for hand felting or in using the above mentioned hand adjustment tip, use a large dish pan in the sink and a metal cookie cooling rack as a scrub board. Use the side that has wires running across your path of friction to give more resistance. Add about 3 inches of hot, soapy water to the dish pan and dip your piece in now and then to keep it hot - there you go!

Anonymous said...

I felt on the stove using a large pot filled about 1/4 full of water and a few drops of dish detergent. The water is heated to HOT! Not boiling. Then I place the item in and use a potato masher to mash the item. After 10 minutes I dunk the item in cold water until the hot water is gone and squeeze it out then return to the pot of hot water again. I repeat this process until my item is felted to the size I need.

Janine said...

I'm very happy to have found your blog! I have been wanting to try felting for a long time and this is so informative I now feel confident to make a start :)

ennadoolf said...

I just hand felted a pair of mitts ! They look great - thanks so much!

Lynda said...

This is a great blog! I use hot water on the stove and ice water in the sink. I have a rubbery mat that sits in my sink to protect breakables while washing. I turn it over to expose raised "feet" for agitation while felting.
I'm hand felting slippers and they are great. Knitted slippers are not a favorite of the men, but the felt slippers fly out the door.

Anonymous said...

This was very good. I knitted a headband and didn't compensate for the bulkier wool and fatter needles, so my gauge was off. Now I have a headband with a heart pattern and want to try felting to shrink it to a normal head size. It might do as a tube top on a narrower shouldered person, however, I think that felting will bring out the patten nicely and I want to try.
I will try the hand felting, but maybe the bamboo mat will work nicely as well. I do have a sushi roller that might work for this small project.
I have used a plunger when washing my lamb fleece and mohair. It resulted in unfortunate partial felting of my favorite brown wool, but maybe I did it too long for fleece. Gentle, gentle, but with the headband is another story.
Thanks for such an informative blog. It was my first hit and I am happy with all of the information.

Anonymous said...

I would like to make felted gloves. How does one know the size to make prior to the felting process? And, please tell me the brand and type of wool to use--and size needles.


TECHknitter said...

Hi Anon--you ask an excellent question. The trick with felted gloves is to make the cuff from superwash wool (or acrylic), with the cuff made to fit, then make the glove above the cuff in wool, knitting them WAAAY too big, larger (and looser in the fabric) than you could ever imagine. When they are finished, put your hands into the gloves, and felt them while wearing them. Keep rubbing your hands together, as if you were washing them, also rub the back of one glove with the palm of another, then switch. Also, interlace your fingers and rub up and down the fingers. Because your hands are in the gloves, you can't use as drastic temperature changes BUT you compensate by using far more agitation. Follow the instructions in the post (add a drop of dish soap, etc), and you will make the most perfect pair of well-fitting felted gloves you ever wore.

Here is a post about making mittens in this manner, it will give you further tips.

Good luck, TK

Cherry Wanders said...

There is also nuno felting which is manipulating wool fibers to migrate through and attach to another fabric like silk. I just made a fabulous Outlander inspired cloak this way and it turned out beautifully.

Anonymous said...

I am glad to have find your blog. Your article was very informative. I felt wool I spun from two sheep I kept as pasture pets a few years. The wool was dirty, even after spinning, but I love to knit clogs and bags and felt them. I think you answered my question regarding re-felting a bag.

I appreciated the tip to turn the article inside out before felting. I use a top loader to felt. I usually use a garment bag. I always include two clean canvas tennis shoes(only used for felting). The shoes agitate and beat the wool better than just the machine agitator.
Thank you, LL