Non-tartan kilts

[OC Richard]

a full blown 8 yard tartan traditional kilt is like a pair of formal tuxedo slacks

In traditional Highland Dress this is not true. A traditional wool 8-yard handsewn kilt is a kilt, period, and can be worn at any time of day or night. The jacket, footwear, accessories etc change to match the formality of the event but the kilt can remain unchanged.

A have a collection of old Highland Dress catalogues from the 1920s through 1950s and some do mention different sorts of kilts for Outdoor Dress and Evening Dress, however the difference appears to be only the weight of the fabric.

For example my Paisleys LTD 1936 catalog gives the following

Paisleys 'Argyll' Costume for Gentlemen (the outfit illustrated is what we would call "Day dress")

Tweed Jacket and Vest
Tartan Kilt (Heavy Quality)
Animal or Leather Sporran
Heather Hose
Flashes
Brogues (Lacing)

Paisleys Highland Dress Costume for Gentlemen (the outfit illustrated is what we would call "Evening dress" with a white wing collar shirt and black bow tie)

Full Dress Doublet and Vest, in Green Refine or Black Vicuna with Roll Collar
Tartan Kilt (Light Weight)
Seal Sporran
Tartan Hose
Tartan Ribbon Garters
Brogues, Patent Leather with Buckle