To celebrate our new location &
12th anniversary, we're having a

Huge Bockens Sale!!

20% Off ALL Bockens Yarn

Select DVDs are also 20% Off!

ALL MONTH LONG!

Sale lasts through March 15th

What's Mercerized Cotton?

Mercerization is a process developed by John Mercer (see below!) in the mid 1800s. By soaking the cotton yarn or cloth in caustic soda (lye), the cotton fibers swell, becoming round rather than flat. The hollow space that is created can then accept dye or other liquids more easily. If the mercerized cotton is stretched during this process, the fibers become straight and smooth, creating a beautiful shine.

Happy Birthday John Mercer!

John Mercer was born on February 21st, 1791 in the countryside of Lancashire, England to a family of farmers. When John was nine, an epidemic struck the district and his father and sister died. John and his remaining family moved in with his maternal grandmother who lived in a neighboring village where he got a job as a bobbin winder at a weaving factory.

When he was a bit older, he moved on to become a weaver, although he didn't particularly enjoy it. He was taught to read and do sums by the factory's pattern designer and taught himself after that through reading books.

It wasn't until John was 16 that he discovered what would become his life's passion. When he was home visiting his mother, his little brother was wearing the BRIGHTEST orange suit and John became "all on fire to learn dyeing." He couldn't find any books on the subject, so he went to the local drugist who sold to the local dyers and bought a 3-penny pack of each dye material they sold. He experimented until he discovered how to create the more common colors and decided to try going into business as a dyer. That endeavour didn't last too long before the Oakenshaw Print Works offered him an apprenticeship in their dye-shop. He accepted, but was disappointed when he was only given jobs of manual labor. When he was 19 was released from his apprenticeship and went back to weaving. He did some dyeing on the side until one fortuitous day he happened to stop at a used book stall and saw an introductory book on chemistry. He purchased it and applied what he learned to his dyeing experiments.

After producing a new orange dye (perhaps this was his favorite color?), he was suddenly sought after as a dyer. The Oakenshaw Print-Works re-hired him, now as their dye chemist rather than an apprentice. He spent the next 40 years there developing dyes and discharges for calico cotton.

In 1844, John was running some chemical experiment where he was filtering various substances through many layers of fine cotton. After coming back to his lab in the morning, he discovered that his solution of caustic soda had transformed his cotton filter, making it thicker and in the center where the solution had sat the longest, it was translucent. He called it "fulled cotton" and set it on a back shelf as an interesting effect. When he retired, he pulled out some of his old experiments and discovered that cotton (or other cellulose fibers) undergo a strange transformation when exposed to a strong alkali solution. He worked out the details and found that he could make cotton cloth stronger, thicker, and that it would take up dye or other liquids more readily. The downside was that the cloth would also shrink considerably. So, although his experiments were interesting to cloth printers, they could not afford to lose as much yardage in their cloth that resulted from the process and mercerization did not become popular until 1890 when Horace Lowe discovered that stretching the material or yarn while it dried created a beautiful shine and the luster we usually associate with mercerized cotton today.

Want to read more? You can read John Mercer's Biography free online. It includes lots of technical details about his dyeing experiments.

Mercerized or Unmercerized for Towels?

Lots of folks call in and ask us what kind of yarn they should be using for towels. No one likes to dry their dishes or countertops and just end up smearing things around. Many mercerized yarns don't work well for towels, but it's not really because they are mercerized! If you read the piece up above, you might remember that mercerization was partially developed to increase the dye take-up in cotton. This means, in theory at least, mercerized cotton should soak up ANY liquid better than unmercerized. In practice however, this doesn't always work out.

So, what's the deal?

It turns out, the structure of the yarn and cloth matters just as much as the finish. Tightly spun yarn in a tightly woven plain weave will repel water more than a loosely spun yarn woven in a structure like huck, waffle weave, or any other weave that creates large floats or a looser structure. This newsletter is too long, so keep an eye out for next month where I'll do some experiments with a few popular yarns and see which makes the most absorbent towels!

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