Vive la Différence -- with Differential Shrinkage

Top photo: handwoven cloth in loom state

Bottom photo: detail of cloth after finishing

"Loom state" describes fabric that has not yet been finished or dyed. In the textile industry, such fabric is also called "gray" or "griege." 

The finishing process is particularly important to weavers because, as I like to say, "It ain't over till it's finished" (with a nod to Yogi Berra). Woven fabric isn't ready to use until it's properly washed. Unfinished or unwashed, it will retain some of the tension that it was under during the weaving process and thus won't feel or behave optimally.

Differential shrinkage takes the process one step further, creating a puckered or pleated fabric, using warm water, gentle soap and lots of agitation by hand or machine. With this technique, one block or group of yarns (such as the turquoise 18/2 merino in the photos above) will full and shrink while the other (the 10/2 cotton in gold) doesn't, creating lots of texture and visual interest.

Deflected Double Weave works well for differential shrinkage because of the plentiful floats and open spaces that alternate with blocks of plain weave. By definition, it has two layers that weave in and out of each other (but never on top of each other, hence the term "deflected").

When I posted some photos on Facebook -- after fulling to create differential shrinkage -- one weaver thought the fabric was stitched double weave. I explained that it only appeared that way because the layers of wool fuse together and the cotton relaxes, losing the gaps between blocks and appearing as if it were one layer.

Here's what the back of the fabric looks like before finishing -- that is, in loom state. (My apologies for the fuzzy image, but I was using my iPhone in reverse to photograph the underside of the fabric while it was on the loom.)

And here's what it looks like after finishing. The cotton blocks in plain weave look almost like they are one layer -- while, before finishing, there are vertical gaps in between the blocks (where the wool blocks are weaving on the other side).

Here are sections of the drawdowns (front and back respectively), which give you a better idea of how the blocks of wool (in blue) might fuse together in the finishing process, making the blocks of cotton (in gold) appear as a single layer. (The technical term here is "fulling" rather than "felting," because we are fusing yarn rather than raw fiber.)

I know there's probably some vibration between the colors in the drawdowns, because they are close to being complementaries -- which is what I wanted! I love the energy of combining opposites or near-opposites on the color wheel.

I proceeded to weave up a number of samples before I cut off the fabric and washed it -- so here are a couple of "before washing" and "after washing" photos.

Back of fabric before washing

Back of fabric (now upside down) after washing

My son, who took both photos -- thank you, Jake -- thought that it looked better BEFORE there was any differential shrinkage. I can see his point, where the fabric may look tidier and more elegant before fulling. After fulling, it might appear to some as messy and wrinkled.

But I like it that way! Differential shrinkage just appeals to me. And there's more to come, as I have maybe 3 yards left on the loom, keeping in mind that 3 yards will shrink down some.... I'm hoping to weave a scarf using these two patterns in sequence.

Thanks for reading!

What Is the Difference Between Fulling and Felting?

Pictured above: a coat of fabric in silk noil and baby alpaca, 

woven in Deflected Double Weave and fulled for warmth and durability

Before I begin, please understand that the coat pictured above is a work in progress: I haven't finished sewing it!

Anyhow, many years ago I was talking with a felter-friend of mine, telling her how I "felted" a hand-knitted hat I had made. She corrected me, telling me that I had really "fulled" the hat -- not felted it -- because felting involves raw fiber while fulling involves fiber that has been knitted or woven.

Here's how the two terms are defined by Britannica.com. (U.S. readers, remember that Brits spell fiber as "fibre.")

Felting, consolidation of certain fibrous materials by the application of heat, moisture, and mechanical action, causing the interlocking, or matting, of fibres possessing felting properties. Such fibres include wool, fur, and certain hair fibres that mat together under appropriate conditions because of their peculiar structure and high degree of crimp (waviness). Wool can produce felting even when mixed with other fibres. 

Fulling, Process that increases the thickness and compactness of woven or knitted wool by subjecting it to moisture, heat, friction, and pressure until shrinkage of 10–25% is achieved. Shrinkage occurs in both the warp and weft see weaving), producing a smooth, tightly finished fabric that is light, warm, and relatively weather proof. A common example is loden cloth, first produced in Austria in the 16th century.

There are a lot of mysteries and opinions (oh my, the opinions!) involving these two processes. Which soap to use? How hot should the water be? Machine wash or hand wash? Do you "shock" the wool by immersing it in cold water after using hot water? Can you heat the fiber in a microwave? And so on. 

I won't be addressing all of these questions; I'm talking about my own hand-woven fabric and how I went about fulling it. Here's the "before fulling" state.

And here's what it looks like after fulling.

And here's another view.

The colors in the photos vary because I used two different painted warps to weave the fabric in Deflected Double Weave. I dyed the silk noil in a range from teal to purple to turquoise and I dyed the baby alpaca warp in a range from lavender to periwinkle to mauve.

You might be thinking: I like the piece before it was fulled. And there's an argument for that, certainly. The main reason I fulled it was for texture: This was to be sewn into a coat and I needed a sturdy, warm fabric for that. I also just love the look of fulled handwoven or hand-knitted fiber: it acquires an organic, more natural look, less angular and tidy -- and to my eye, far more interesting!

Here's a photo of the back of the coat to give you a better idea of what I am going for.

The fulled fabric has a bit more eccentricity and quirkiness, in my view.

I've long pondered the question, "What makes wool felt?" The simple answer lies in the microscopic structure of the fiber. It has tiny scales on it that open with heat and soap and agitation (and pH, when you get really scientific about it) and then lock into each other as the agitation continues.

Here's a photo I found on Pinterest that gives you a microscopic view of a number of fibers. Unfortunately, I can't find where it's from because it's all over Pinterest, with no attribution.

See the scales on the coarse wool and fine wool (first and second fibers on the left)? And see the smaller less defined scales on the alpaca (third from left)? 

Many people will tell you that alpaca can't be felted or fulled -- but that's not really true. It's just that it takes longer to do so.

And I can testify to that. Without going into all the gory details, it took me several days of washing and sloshing my 8 yards of fabric in the bathtub, in the sink, and even in the washing machine. There's even some nudity involved but I won't go into that on a family blog ;o)

I just wasn't getting the results I wanted -- and then I remembered a spinner telling me that she used Murphy's Oil Soap to felt her wool. Murphy's is slightly basic, at a pH of about 11, and that change in pH helps the scales to open which in turn promotes their locking together.

So I tried Murphy's and yes, I did get the results I was after. Not perfect, but close enough. 

And I learned a lot in the process -- which is half the reason we fiber folk enjoy what we do! Thanks for reading.