These spaced dyed, slub yarns work well in the warp as well as giving beautiful results in the weft. Just put the slub yarn through the slots and not the holes to give the threads plenty of space to move around. This way they won’t come under too much friction as you move the heddle up and down. Wind the yarn on in pairs in the usual way and then wind the warp onto the back beam. Then when you start the threading you can move the slub yarns around and put them through the slots in what ever order you like. This is one of the reasons why the rigid heddle loom is such fun to use as it gives you lots of opportunities to make changes to your design as you thread up your warp.