Quote Originally Posted by M. A. C. Newsome
But the difference between a "tartan" and a "plaid" is not the difference between two types of design. It's the difference between a certain kind of garment (plaid) and the pattern of cloth that the garment is made from (tartan).

Aye,
Matt
(Not "shooting anyone down", just dispensing knowledge!)
Thank you Matt for being so patient in explaining this. The use of the word 'plaid', when what is really meant is 'tartan', seems to be confined to North America. No one in the UK would refer to tartan as 'plaid', and we (on this side of the pond) tend to smile in amusement when we hear Americans refer to plaid, when it is obvious that they really mean 'tartan'.

Rob (who wears a tartan kilt, but not a plaid)