What we call Plaid originated in Scotland where it’s Tartan. It’s the pattern you see in kilts, those traditional man-skirts worn by the Scots. It’s a kind of checkered pattern where the crisscrossing stripes are of the same or different colors, and their intersections are a merge of the thread colors.
Kilt in the Royal Stewart, the personal tartan of Queen Elizabeth II
The pattern comes from the weave. Pre-dyed threads, originally wool, were alternated with each other in a twill weave. One long thread serves as the weft, going back and forth the width of the cloth, intersected by the warp threads going along the length of the cloth, at right angles with each other. The weft is woven in a simple 2/2 twill, two over then two under the warp. A solid color is produced where a thread crosses another of the same color. An equal mixture of the two colors is created when threads of different colors intersect. So 2 different color threads create 3 colors. 6 different color threads create 21 different colors. The more stripes and colors are used, the more subdued the patterns become.
Initially, the local weavers and local tastes were responsible for the tartan patterns, largely a result of the local dyes available in an area. Transportation of dyes from faraway places at that time was prohibitively expensive. The wearers just chose from the available colors and patterns.
Around the middle of the 19th century when many patterns along with chemical dyes became available, they started to be associated with certain Scottish clans and institutions especially among those who wanted to be identified with Scottish heritage. Tartan became the national dress of Scotland.
It was a visit of a reigning monarch that got Tartan to the world stage. King George IV visited Edinburgh, Scotland in 1822. Sir Walter Scott who founded the Celtic Society of Edinburgh urged Scots to attend the festivities of the royal visit “all plaided and plumed in their tartan array.”
Two years later, Queen Victoria and her husband Prince Albert visited the Scottish Highlands and later bought Balmoral Castle in Aberdeenshire, Scotland. Prince Albert personally took care of the interior redesign and made great use of Tartan on the carpets, curtains, and upholstery. They then spent a great deal of time in that estate, hosting many Highland games where their children were attired in Tartan.
Inside Balmoral Castle
Tartan became an English royalty favorite. Queen Victoria designed the Victoria Tartan, while Prince Albert the Balmoral Tartan. One of the most popular tartans today is the Royal Stewart tartan, the personal tartan of Queen Elizabeth II. It is also the most regal of fashion patterns in the fashion world today.
A big piece of tartan pattern cloth was called 'plaid' in Scotland, so Plaid caught on as a name for the pattern popular in America. Indeed, plumed in a Plaid tie calls on the tartan pattern that stirred royalty.