WHICH HEDDLE? - Rigid Heddle or 4 shaft looms -Calculating warp and weft

      Many more people are beginning to weave thanks to the new rigid heddle/knitters looms. Great, attractive pieces are being woven by beginner weavers and I think this is wonderful! I have enjoyed the craft for many years but previously rigid heddle looms were not as attractive or portable as they are now and the implication was that you need to use specialised weaving yarns to produce anything worthwhile. That is certainly not so and the choice of yarns is extensive and inspiring.
But one factor in the success of a project can still be overlooked and that is the use of the correct heddle for the project and result required. Most yarns are expensive and it is a shame to waste yarn and your time, as well as being so disappointed that you never want to weave again, as happened to a friend of mine just a few months ago!
      I am happy to say that she has resumed weaving and is making successful progress.

       Some time ago I damaged one of my tape measures but I chose not to throw it away! I soon found a use for it. While I was sorting through my stash of woollen weaving yarns I decided to store them according to their character and thickness. I stapled lengths onto pieces of card and wrapped each yarn around a 2" length, at the same time as recording  the number of wraps per inch on the card I wrote, where available, the manufactures yarn specification.Wrap the yarn so each wrap lays side by side with the one before, without cramming or over crowding each other.

      To be most accurate it is a good idea to do this over a 2" length.

      The Shetland style yarn samples above which wrap 20 times to the inch.  If they were to be woven with each other as warp stripes or one warp and weft in a typical plain/tabby weave (over one under one, over one under one, all the way across the warp,) would be suitable for a 10 dent (threads per inch) heddle whether on a Rigid Heddle loom or one with multiple shafts.That is half the number of wraps per inch
The reason for this calculation is that the space between the warp threads is the diameter of the weft yarn and so gives it room so it doesn't distort the woven cloth.
It also means that the weaver should be passing the shuttle of weft yarn 10 times from side to side to produce one inch of woven fabric, thus creating a 'balanced' cloth where, on the face of the fabric the length of each yarn, warp and/or weft, showing on the surface will be the same. Look at any plain weave cloth and this should be the case.

      In short, if you are using the same yarn warp and weft on a rigid heddle loom, or for a 'tabby' weave on a shaft loom, to get a balanced weave structure:-
a yarn that wraps 24 times to cover an inch needs the warp to have 12 threads per inch and be woven with a 12 dent heddle (reed on a shaft loom).
24 wraps per inch = 12 dent heddle
20 wraps per inch = 10 dent heddle
16 wraps per inch = 8 dent heddle
15 wraps per inch = 7.5 heddle, and so on.

If you intend to use one yarn for the warp and something different for the weft, it is best to wrap them both alternately, as shown on the next sample.

    When using the brown as the warp with a thicker, slightly slubby yarn for the weft further wraps had to be produced to be sure of success in the woven fabric. The photo here shows that 8 brown warp ends to the inch would be appropriate for a tabby weave. Using 2 different yarns or colours of the same yarn alternately makes the task of counting the wraps per inch for the warp much easier. (It can be frustrating when you lose count and have to do it over again!)

      In fact I decided to weave a twill cloth with brown warp and lighter tweedy weft. In a regular twill weave the weft passes through the warp after 2 threads/ends. This means calculations are slightly different. Two wraps of warp yarn are followed by one of the weft. As you can see from the photograph this meant I needed 12 wraps/ends of brown shetland per inch width of cloth. A 12 dent heddle was needed for this cloth.

Balanced Tabby Weave 

      The following examples are woven in Tabby - over and under alternate threads. The red is handspun wool yarn used both warp and weft. The following 2 are wild silk, both using the same unplied wild silk yarn. The checks were created with a warp, two threads of each colour in turn in both warp and weft. The third sample is log cabin. ( See my blog article - PREPARING TO WARP YOUR LOOM also 'The Next Steps.') I think you can see that the weaves are balanced.

What does this mean to the weaver planning a project? 
      If the space between warps threads is too great the weft yarn beats down to cover more of the warp than expected and the weft yarn will dominate the cloth rather than it being balanced, showing warp and weft yarns equally. Also, more weft yarn will be needed to complete the length of cloth!

      This is the yarn for my latest project, still on the loom.

       The photograph shows that the warp yarn is much thinner than the weft but the finished fabric will still be a balanced twill - hopefully! Watch this space.