I have used a red cotton poplin. I can't remember if it has a touch of elastane in it as well. Here is the front:
The back ( couldn't check my rear view, so pleats are a little weird)
From reading the instructions, I wasn't sure exactly why it was given an advanced rating but after completing it, I now know. Each piece looks like a squiggle, it is very hard to tell each piece from the next and look at all the pleating. It comes together beautifully, it is just time consuming.
If I get into the state finals, I am going to have a beaded hairclip and necklace made up.