How Many Years in the Switch from Box to Knife Pleat?

[OC Richard]

The first real documentation I can cite for the use of the side, or knife pleat is when the Gordon Highland regiment began making their kilts this way in 1853.

That's very very interesting. Makes me wonder how many early military kilts are sitting around in various regimental museums, and if anyone has ever examined them all to see how they're pleated.

In the 20th century, the kilts of the Black Watch and Gordon Highlanders were knifepleated, outnumbered by the kilts of the Cameron Highlanders, Argyll & Sutherland Highlanders, and Seaforth Highlanders which were boxpleated.

If the Gordons switched to knifepleats in 1853, then when did the Black Watch change? Or were they always in knifepleated kilts?

Today there's just the Royal Regiment of Scotland, which wears the kilt of the Argyll & Sutherland Highlanders, meaning that all Scottish infantry today wears boxpleated kilts.

All of this doesn't answer the question why, in the Highland Dress as it came down to us from the early 20th century, were civilian kilts always knifepleated, and nearly always to the tartan? (I now have quite a collection of old Highland Dress catalogues and kilt pleating isn't mentioned- knifepleated to the tartan is assumed, evidently.)

Why did only the military perpetuate boxpleated-to-the-stripe kilts?