I bought three colors of yarn, but after I placed my order I realized two of them were 8/2 cotton while the neutral color was 16/2. I am planning to weave towels. Can I double the 16/2 natural, and if so, how do I adjust my weft? I will be making a plaid pattern. Should I just stash that yarn and purchase the 8/2?
You can definitely use the 16/2 yarn and double it in both the warp and the weft. One advantage to having 16/2 is that you can use it singly for the parts of the hems that you turn under.
To double the yarn in the weft, there are two options: winding two threads onto the bobbin, or making two picks in the same shed. Both have drawbacks. The two yarns will often unwind from the bobbin unevenly, and weaving two picks takes twice as long as weaving one.
I often choose to weave two picks in the same shed (you have to add floating selvedges if the structure is plain weave). I enjoy the weaving process, so making twice as many picks does not seem like a bad thing. It is also faster and more pleasant than fiddling with the selvedges on each pick if two strands are wound on a bobbin.
Using a two-bobbin shuttle takes some practice but once you get the hang of it the two threads will roll off at the same speed. Photo by Madelyn van der Hoogt
Another option is to use a two-bobbin shuttle. Managing this shuttle takes a bit of practice at first, but you soon learn to throw it with just the right force to turn the two threads together.
(Of course, you could always purchase the 8/2 and start dreaming about projects for that 16/2!)