So the sett as you call it is 6" on this after measuring it out.

Actually I think good news I retackled this tonight and pleated in a new way that allowed me to fudge the distance by a few milimeters on each pleat. by running the color together on each fold I could create a little more distance than 1.5" just a tiny bit. On the last pleat which comes back to face the other one I found a shortcut on that that saved a few inches. By the end my inner apron came out to 19.5 inches which is within 1" of where I wanted it to be. So it will be doable like that. It was only coming out to about 14" before.

The total distance of my pleats came about 1" shorter than what I wanted but I still think it will be pretty good. The other kilt I was going off of for my measurements was always kind of big for me so I think i'm close enough with this one. I'm going to --with the help of my mom's sewing machine have this up and done by this weekend and I'll post pics when I'm done. My outer apron is 2.5" too big but i'll just put some extra hem on it.

One thing I wanted to figure out is how do people put the frizzy into the material of the outer apron. Kind of like it is in this picture.