I'm sure you've all come across it once or more in your online travels: the Saltire kilt, pleated "to the flag". I'm still undecided on whether I like it or not, but I've racked my brain many times over how this can actually work with a regular weave of tartan - especially since the apron gives no hint how it's done. Can anyone explain exactly how it's done? If it is woven 'normally', what would it look like before pleating?

I have a strong suspicion there's some sort of cheating going on, but a striking effect nonetheless!

Here's a pic, for those who have no idea what I'm on about: