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The nice wavy effect is just the glider system, and can be had from other manufacturers than silent gliss.
The gliders are on a string and can rotate and the distance between gliders/hooks and the amount of fabric in between creates the waves. Can't find the brand I used, and as I am in Germany you'll probably have different systems, but my new curtains are standard tracks and cheap fabric.
After seeing the silent gliss wave curtains on here the plan is to have a recessed track for that across the big window.