Inches are used pretty commonly in weaving. I suspect this reflects the dominant weaving countries and certainly weaving on the internet, but for those of us in a metric place I think it’s probably easiest just to use a ruler that shows inches too!
So, with that in mind, I’ve been using a ruler that shows inches to measure my reed, my warp and my weft. These are the main places where we need to measure x/inch.
First, let’s consider the reed. It looks a bit like a comb, as I’ve mentioned before, and like a comb it has teeth (solid bits) and gaps. In weaving we call those gaps dents. So when you see a reference to a 10 dent reed, that means there are 10 gaps in every inch across the width of the reed.
Why do we care? Well, those dents help us to space our warp threads. Remembering that the spacing of the warp affects the final density of our cloth, you can see it’s important to have the right reed. (This applies also to rigid heddle reeds, with the dents being both slots and holes.)
It’s also important to know how many ends per inch you need, with an “end” being a single warp thread. (Weaving loves multiple terms!) So, if you want a balanced weave, you obviously want to know how many ends per inch (e.p.i.) and how many picks per inch (p.p.i.), where “picks” means weft threads.
There is one more x/inch measurement, and that is wraps per inch. This refers to taking your yarn and wrapping around a ruler. Why do this? Well, that’s how you start to work out how many dents per inch and ends per inch you need! I’m coming back to that in an upcoming post – think we’ve all had enough x/inch for now.