In my store I have a few silk scarves with a wavy effect all the way down the length of the scarf. This is made using an Ondulé or Fan Reed.
Whilst the usual reed, which is used to "beat" the silk weft into place, is sitting in a holder that can be moved backwards and forwards, the height of the Ondulé reed has to be adjusted every few throws of the shuttle and therefore has to be attached to the loom in a way that allows this to happen. Every loom is different so there is no one size fits all method. And of course, because the height has to be adjusted every few picks, the weaving takes much longer.
A while ago I made a couple of videos showing how I have attached the ondulé reed to my loom and how I adjust it during weaving. Bear with me - I was on my own and had to fix the camera in place and hope for the best : it's not perfect but I think you will get the idea! Anyway, if you have any questions please feel free to ask me.
There are two videos each with me trying to explain what I'm doing. The castle I refer to is the main body of the loom holding the shafts.
I tend to only weave two Ondulé scarves at a time. I have to lean forward when I'm weaving and my back starts to complain. But the results are always worth it