There is a weaving problem in overshot that has been bothering me for a long time. In the May/June 2014 issue, for example, I found the “Rose and Star Overshot Towels” (by Robin Spady, pages 30–33), which I love and started to weave. Instead of the recommended 10/2 pearl cotton, I used 22/2 cottolin (in white for the warp and tabby weft, in blue for the pattern weft). The towels in the magazine show the pattern weft (blue) as the dominant color, and the section for each design is a square. With my cloth, white is dominant and the design squares are elongated (about twice as high as they are wide). I was wondering if to avoid this problem the white yarn should be finer than the blue one. Or is there any other solution?
You did not say what your warp sett is, but I’m guessing you used the recommended sett in the article of 24 epi for the cottolin. 22/2 cottolin (at 3,200 yd/lb) is heavier than 10/2 pearl cotton (at 4,200 yd/lb). For your blue pattern weft to cover the white background and weave the designs to square, you would have to have achieved 48 picks per inch (24 pattern/24 tabby). Your weft sett was probably more like 28 or 30 picks per inch. That gives a much higher percentage of white warp and tabby weft relative to the amount of blue pattern weft and lets the tabby weft show between pattern picks. A sett of 20 ends per inch would have been better.
Another issue is that in most overshot fabrics, the pattern weft yarn is two to three times thicker than the warp and tabby weft yarn so that it will cover the pattern blocks well. It is not thicker in these towels because the overshot floats are so very short. In this case, a heavier pattern weft would be harder to beat in (the pattern weft itself is doing so much interlacing). The ideal pattern weft is soft and lofty, so it will beat in yet cover the overshot blocks.
Cottolin is a firm and matte yarn; pearl cotton is very smooth. It’s therefore easier to beat in a pearl cotton weft than a cottolin weft. I’m not sure you could get the pattern weft to cover completely in cottolin of the same size as your tabby weft if you opened your sett to 20 epi, but I’d try that first (then maybe even try 18 epi). If there were a soft, lofty cotton that you could use for the pattern weft instead of cottolin, that would help, too!