One of these days, I'm making my own pinch-pleat draperies. I've wanted them for a while, but everything in the stores is really expensive (if you can even find nice looking drapes), or they are really nothing but glorified curtains. And I have perfect instructions right in my BH & G Sewing Book binder, printed in 1970. This is the divider for the "Sewing for the Home" section:
For anyone else who wants to learn more about it, who might want to try it, here are some images from the book, showing the process:
Keep watching for "Slipcovers" and "Bedspreads!"