Thoughts on Wet Felting and Fulling

Pat Spark, 1998

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        Felting is usually considered to be the first stage of the entire process of making a piece of felt. It is the stage in which the fibers are subjected to moisture and agitation. They entangle on each other to form a cloth. This cloth is not hard, nor has it begun to shrink. In this stage, the fiber is moistened and the scales on the outside of each fiber begin to open up because the moisture goes into the core of the fiber and causes it to swell, thus pushing out the scales which surround the core. When you put your hands on the fiber and start to gently massage it, the fibers themselves begin to move. (Slight movement that is not readily noticeable by eye.  If you are making the fibers move a lot with your hands, you are pushing too hard.) Because of the way the scales are positioned on the shaft of the fiber, the fiber itself can only move in one direction. (It can move towards the place where is was cut off the skin of the sheep, i.e. the root of the fiber.) When the fiber was laid onto the felting table prior to being wetted, it was probably placed in carded batts of criss-crossing layers. So this means that the fiber was already laid out with the roots of each fiber laying in a different direction from the ones around it. When the fibers move forward towards their root, they curl around the fibers next to them because of their crimp. (The waviness of the fibers.) As they curl around each other, the scales catch on each other and become entangled. Another name for feltmaking is massive entanglement. The fibers are massaged until they are entangled enough to have created a fabric which holds together as one mass.
There are some tests to see if you are finished with the felting stage.  You can try to gently push the fiber with your finger.  If it moves, it is not ready.  If you are doing a one-sided laminated felt, you could look at the cloth side and see if the fiber has worked its way through the laminating cloth.  If so, and if the fiber doesn't move at all when gently pushed, it is ready.  Another, more aggressive test is called the pinch test. After working the fiber for a while (the length of time depends on the type of fiber used), use your thumb and forefinger to gently pinch and lift a little fiber on the surface of the textile. If individual fibers come up, the textile is not through the felting stage. If they hold onto the fabric around them so that the whole fabric picks up as one unit, they are through the felting stage. This felt fabric is ready for fulling to make it tougher. If used without fulling, the fabric will likely pill and shed fiber until it falls apart.
        Fulling refers to the use of heat, moisture and extreme agitation to make a wool fabric shrink and therefore become stronger and warmer. This fabric can be made by felting, by knitting, by weaving, by crocheting, by knotless netting, or any textile construction technique that can use wool fiber or yarn to create it. When fulling is being done, the fibers continue to move (we call this migrate) and entangle on each other. Even though the size of the fiber diameter does not change, the air between the fibers is removed as they tangle around each other, so the fabric "shrinks".

Here is a compilation of things I have written on the internet about fulling.

Definition of Fulling:

Dec. 2002. Question: What is fulling? Pat's Answer: Fulling is the process of taking a cloth made of wool (could be made by felting, knitting, weaving, crocheting, etc.) and then using vigorous methods to make the cloth become a felt.  It is the late stages of the feltmaking process.

Fulled Weaving:

February 1997, Question: What does the word Vadmal/Wadmal mean?  Pat's answer: According to my Swedish dictionary, vadmal (wadmal) is a heavily fulled, woven cloth.  Also, Kerstin Gustafsson in her book Ull (Wool) writes: "How hard should a cloth be stamped (beaten) in order that it can be called vadmal?  There isn't any given measurement, but that the cloth will be called vadmal when it is so tightly stamped that no warp or weft threads can be pulled out of the cut edge.  If it isn't so tight, it isn't vadmal, but a cloth that is more or less fulled/finished.  These can also have a brushed surface.  A true vadmal cloth is never brushed."  (P. 183, How Much Should It Shrink?) This goes along with my understanding of vadmal (wadmal) that it is a woven cloth.
      Personally, I like the terms knit felt and woven felt, since they both use the word felt which implies that the initial textile structure is obliterated by the extreme fulling process.  I have fulled my knitting and my weaving in the past, but I have not always made them into a "felt".  Gentle fulling will plump up the fibers and cause the spaces between them to fill in a bit, thus making them warmer.  But the initial structure can still be seen. These are not knit or woven "felt".

Fulled Knitting:

June 1996, Question: How do people full their knitted yardage?".  Pat's answer: I do some fulled knitted, but the people I know who have really been researching this area are Therese Inverso and Lene Neilsen.  Therese has written several articles for Threads on fulled knitting.  She actually uses old thrift shop sweaters and fulls them in the washer.  She has written a nice article on piecing with these fulled textiles for the upcoming July issue of the North American Felters' Network newsletter.  Lene has written in her felting magazine (Felt/Filt) a couple of times about combining handknit fabrics and fleece together to create interesting new fabrics.  She reviewed a book by an English author which is totally devoted to fulled knitting.  I'm sorry I can't remember the name or the author.     
        I remember reading an article several years ago in Threads about a woman who fulled yardage she had machine knit.  She used a merino yarn.  To keep the selvedges of the yardage from distorting during fulling, she whip stitched the two selvedge together to create a large tube of knit cloth. Then she fulled it in her washing machine. 
        I saw some washing machine fulled, knitted cloth for sale at a sewers convention.  Again, the woman used merino yarn and machine knit the original yardage.  Then she fulled it in the washer.  I don't know if she sewed the selvedges together or not.  (It was her trade secret and she wouldn't talk too much about it.)

May 1998, Hi Rose, most of us make our felt from fleece, and do not knit the fabric before it is fulled.  Since I haven't done very much of this, I really can't give you any hints.  The easiest thing to do might be to make a yardage, that is knit a piece of cloth, then baste it into a tube (with a nylon or sythethetic non-wool type yarn) and full it in the washer.  I know that people do this with machine knitted cloth so it should work with hand knit cloth.  In this way, the tube shrinks pretty evenly and you don't get the rippling associated with fulling flat sheets of cloth.  I would think that it would be hard to predict that the vest would shrink exactly where you want it if you knit the vest first, and then fulled it.

November 1998, Kelley asks: Is there a difference between wool felt and boiled wool?.  Pat's answer: Wool felt usually refers to "true" felt, that is felt made from wool fleece without any yarn being involved.  Boiled wool usually refers to a felt-like cloth made from yarn (either woven or knitted) which has then been subjected to the fulling conditions of agitation, change in pH (usually to alkaline), heat and moisture.  If one can no longer see the weave or knit structure, the cloth would be called a "knit felt" or a "woven felt".