george,

Sephy's kilt is made from Marton Mills P/V. The same fabric that Rocky and McHummel use.
And the same fabric the next run of X Marks will be in.
This fabric, being a synthetic material, is very resistant to wrinkling and if the proper temp is used when pressing the pleats they are virtually permanent.
I have a P/V kilt that has been through probably 50 washing machine and dryer cycles. It looks just like it did the day I made it. I have never re-pressed the pleats.