What is a sloper?

A sloper is

1. A fabric model of a garment made to fit a particular body
2. What is taught at Don McCunn's excellent online classes (his book is also great)
3. What I should have done with my daughter's skirt as soon as I realized the waistband had 30 pieces

My daughter received the skirt I showed you in the other posts, and boyhowdy did I get the sizing wrong. There were no size measurements on the Burda pattern itself, so I took a Burda magazine and compared her measurements again that to find a size, then made the skirt to fit that size. However, that was 2 sizes too big! Note to the world - Burda magazine sizes do not have the same measurements as Burda patterns.
While I'm waiting for her to return the skirt, I took the time to make a sloper. Sewing the sloper went amazingly fast as soon as I created a waistband out of one piece instead of the 30 pieces I used earlier. The skirt was ready within 2 hours.
I always make slopers out of the cheapest fabric I have that is roughly similar to the fabric I want to use in the final skirt. The fabric used in this skirt is a 1 Euro per meter cotton I bought at a factory outlet (Hilco in Leinfelden-Echterdingen).
This skirt was made to fit her waist exactly, and I measured twice to be sure. Then I had enough time to put the ruffles on as well before mailing it off to her.
Here's how the finished sloper looks.

The nice thing about slopers is you can mark them and can take many shortcuts in construction, since you are just using it for fitting. So I marked the waistband, and the waist level, so she can put it in exactly the right place. I also made two different kinds of ruffles, and marked the place where she can compare before telling me which one she prefers.
Here are the markings.

Finally, I used velcro instead of a zipper because it was faster to sew and my girl can adjust it to fit if changes are needed. And I can keep the sloper as long as I need, to compare to other things I sew for her.