Fun Facts about Tartan 

• Tartan (the word) most likely comes from French
  Most likely it is derived from the French words tartarin meaning Tartar cloth and tiretaine, which stems from the verb tirer (to pull). But it has also been suggested the term comes from the modern Scottish Gaelic tarsainn, meaning across, or from the Spanish tiritaña, a type of silk cloth, or the Gaelic breacan, meaning plaid or speckled.
  

• Tartan didn't originate in Scotland - it came from Central Europe
  Textile historian E. J. W. Barber tells us that the Hallstatt culture of Central Europe, which is linked with ancient Celtic populations, produced tartan-like textiles between the 8th and 6th centuries BC. Tartan, as we know it today, didn't exist in Scotland until the 16th century and tartans didn’t become associated with specific clans until the 19th century. Before that people picked their plaids based on the colours, just as they do now.
  

• Clan tartans as we know them basically stem from the early 19th century - here's a BBC clip on that topic

• Queen Victoria is partly to thank for tartan’s popularity today
  When she turned up to the Great Exhibition in 1851 with her young sons, Albert and Alfred, decked out in full Highland attire, sales of plaid went through the roof, and became a particularly popular choice for school uniforms.
  

• Tartan Day is celebrated in some countries, including Australia, on July 1
  July 1 is the anniversary of the repeal of the  1746 Act of Proscription, which banned the wearing of tartan in an attempt to control the Highland clans that had supported the Jacobite Risings.

• In the US Tartan Day is celebrated on April 6
  April 6 is the anniversary of the Declaration of Arbroath - the a declaration of Scottish independence, made in 1320. The Declaration, dated 6 April 1320, was a letter in Latin submitted to Pope John XXII. It was intended to confirm Scotland's status as an independent, sovereign state and defending Scotland's right to use military action when unjustly attacked. The most widely quoted section reads
  

for, as long as but a hundred of us remain alive, never will we on any conditions be brought under English rule. It is in truth not for glory, nor riches, nor honours that we are fighting, but for freedom – for that alone, which no honest man gives up but with life itself:

• The world’s first colour photograph was of a tartan ribbon
  During an 1861 Royal Institution lecture on colour theory, James Clerk Maxwell presented the photo, taken by Thomas Sutton, inventor of the single-lens reflex camera.
  

• An astronaut took his tartan to the moon and back
  In 1969, Alan Bean, the fourth man to walk on the moon, took a piece of MacBean tartan with him on his journey .It is now in St Bean Chapel in Fowlis Wester, Perthshire.
  

• Tartan is hugely popular in Japan
  Tartan is a staple of Japanese street and runway fashion. Designer Jun Takahashi once had models strut down the runway painted from head to toe in plaid and he country has had several tartans dedicated to it - even Hello Kitty has her very own tartan.

• Elvis Presley had three tartans to his name
  Because he is said to have roots in Lonmay, a tiny village in Aberdeenshire,  in 2004 local designer Mike King created an official Presley of Lonmay tartan in his honour followed by a modern version a few years later. The Scottish Tartan Registry also lists the Presley of Memphis tartan by Brian Wilton, which is based on the colours of the US flag with a gold stripe to represent Elvis’ multiple Gold Discs. It even has a thread count of 42 – the age the King was when he died.
  

• There really are Tartan sheep
  The owners of the East Links Family Park near Dunbar and the Auchingarrich Wildlife Centre in Perthshire have been known to paint their sheep tartan for Tartan Day and other events.
  

"I’ve been telling all the kids that come to the farm that I have connections with the Clan McHaver," says Grant Bell, "and  that I’ve managed to get a few of these rare sheep sent down from the Highlands. I tell them the lambs are actually born a light shade of blue and don’t become fully tartan until they are around one year old. Their tartan wool is prized by kilt-makers all over the world, and the whereabouts of the Highland glens where the clan McHaver – who have bred and tended the flocks of tartan sheep for centuries – is a closely guarded secret."

The sheep have become a tourist attraction in their own right, with the Auchingarrich flock even featuring in an episode of Come Dine With Me.

• Quite a few of the more than 7,000 variations of tartan registered with the Scottish Tartan Register are not clan tartans
  Irn-Bru, CocaCola, Edinburgh Zoo Panda, Harley Davidson, the FBI, Harley Davidson, the Hard Rock Cafe, Lady Boys of Bangkok (the dance troupe) all have their own tartan, as do America, the European Union, Ellis Island, New York City, New Jersey, New York City. There are even Peter Rabbit, Peter Pan, The Scotsman (the newspaper), Titanic, Hello Kitty, and Christmas (the festival) tartans, and both a Jewish and a Sikh tartan.

• The Australian National Tartan is red, white, and  blue, from our national flag. The six white stripes represent the Southern Cross, the green and the gold are for our formal national colours, and the black stripes in the tartan represent Australia's early beginning as a convict settlement. And the Brisbane Tartan is blues and yellow, the city colours.