How much under 6 inches is the sett? When I did my dad's box pleat kilt, I used one and a half setts per pleat. The sett in this case was close to 6 inches, maybe a hair over. So each pleat used roughly 9 inches of material. Therefore each pleat was 3 inches wide. And in effect, pleated to the sett. Matt Newsome made the suggestion to me when I ordered the material. I'm sure if you did a search in the DIY section for Barclay dress, you might find my thread on it. Here's a shot of the pleats.



Good luck. I hope this helps.