I didn't have a zip let alone an invisible one, but I rip one from a skirt awaiting the quilting pile!
I'm quiet happy with the fit as it's supposed to be below the natural waist, so I was planning near my belly button which seems to work. I really like the waist band version but I was time conscious and didn't want to have to go through tutorials.
The hardest part was defiantly the scalloped hem. The joining bit between each scallop could be more precise.
I worked harder on the pleats tieing the ends off. I used more pins to keep everything in line. I should have used the iron more. And finally I plan to get a better zip.
As this is a wearable muslin I am planning to do just that! So I am not making up the skirt again in a hurry although I do have fabric waiting in the wings. This is mainly because I want to see if I like to wear it and how it wears throughout the day.
So how's the Colette Sew along going for you?