The first step was to find our yarn. We had considered spinning the yarns from the raw cotton fiber, but given that organic, unbleached cotton yarns already exist on the market, we figured it would be better to support these businesses.
We knew we wanted organic cotton. But what about the rest of the details? Just as with every step of this process, there were a number of different factors to consider.
Yarn Weights and Plys
All denim is woven with a 3/1 warp facing twill, and denim, being heavier and tougher than most fabrics, requires a thicker yarn than most. When sizing yarn, the simplest and most widespread way in the spinning industry to describe yarn size is to use English Cotton Count, abbreviated with Ne.
The first number after Ne is the yarn weight, which is calculated by how many 840 yard lengths of the yarn there are in one pound. (The reason for that number being that there are typically 840 yards in a dyeing hank). Therefore, the lower the number, the heavier or thicker the yarn. Lighter textiles start at around Ne 12 or 12.5.
The second number that often accompanies yarn size descriptions is the ply count. This means how many separate strands are spun together to form one yarn. It is the final yarn that is used to calculate the above yarn weight number. Ply count signifies a stronger yarn, not necessarily a heavier yarn. Single plies are represented either by a "/1" or a lowercase s after the yarn weight. All other plies are written as a "/" and then a number.
Ne 10s means there are 8,400 yards in a pound of yarn, and the yarn is a single strand.
Ne 12/2 means that there are 10,080 yards in a pound, and the yarn consists of two strands twisted together.
Yarn Weights for Denim
Typically, denim uses yarns from Ne 4s to Ne 12s (4 being quite heavy and 12 being more similar to what you'd see a tablecloth woven out of). The "s" that follows each number indicates that the yarns are a "single-ply", or only one strand of fiber makes up the yarn. This is most likely an industrial standard, as machine looms can handle single-ply yarns without much issue. However, when hand looming, using a single ply is generally not recommended, due to the likelihood of breakage. It is also extremely difficult to find individual cones of single ply that aren't industrial sized minimums. 2-ply would be just as thick and heavy as a one-ply, only stronger.
The yarn we ultimately selected was an Ne 10/2 cotton yarn. This weight would be thick enough to make a sturdy denim without being too heavy.
Organic Cotton
The yarn purchased for this particular project was 50% organic and 50% EZ Dye cotton, also known as Dye-Lishus Cotton Yarn. It's your typical 10/2, ring-spun, carded cotton yarn with one twist. It doesn't take any additional mordant or treatment to bind to the dye. The concept was brought to the hand-weaving community by a woman named Eileen Hallman of New World Textiles. The EZ Dye aspect of the yarn is achieved by adding a molecule to the cotton cellulose that attracts and bonds to dye molecules. This process occurs even before the cotton has been spun into yarn. As a pre-mordanted yarn, the cotton no longer requires salt, washing soda, or other treatment chemicals. More dye is taken up by the yarn, reducing dye and chemicals in the waste water, and less rinsing is needed after dyeing.
While the yarn was great and yielded a nice color after dyeing, in retrospect, we probably could have gone with a 100% organic cotton yarn, without the EZ Dye element. Indigo dye, as we soon learned, does not require a mordant on the fiber to bind to the yarn. More on that in the next post.