Determining Sett

Day 157: When you're planning a weaving project with an unfamiliar thread/yarn, you need to determine the proper sett if you want to achive a balanced weave. For a tartan to be authentic, it must adhere to the proportions described in the Scottish Register of Tartans. It should be a 50/50 weave, which is to say that it should have the same number of warp threads and weft passes in an inch. Given the variation between yarns, how do you figure out the correct sett? A good starting point is by ascertaining the number of wraps per inch (WPI). Wind the thread around a ruler with each wrap taken as close to the previous one without compacting them. Cover an inch on the ruler and count the number of wraps. Divide the WPI in half if you plan to weave tabby, or by 2/3 for twill. And I cannot emphasize this strongly enough: this is only a guideline! You may have to adjust, as I did for my 16/2 Scottish wool. It wrapped the ruler at 40 per inch. This suggested at 30 warp ends per inch (EPI) would be a good sett. However, because this wool was very expensive and I only have enough to weave a shawl in my McLeod tartan, I decided to make a sample to confirm the sett. At 30 EPI, I made 40 weft passes to the inch ("picks per inch" or PPI), obviously not a 50/50 weave! Yes, I could still weave perfect squares, but my goal was to weave my official tartan, not just a plaid in McLeod colours. Therefore, I had to make some adjustments. By changing the sett to 36 EPI (tighter), the weft picks didn't pack as firmly. I'd found the sweet spot, although it will still take some careful attention to beating to keep consistent throughout the piece. I think my mother would be proud. (Footnote: the McLeod of Lewis tartan is mostly yellow and black with a fine red line, so I wove this sample using red because I knew I'd have more than enough. The yellow in the photo is not wool. It's a piece of nylon cord I used as a separator.)