Quote Originally Posted by ctbuchanan View Post
According to my mum who was born in Scotland, this is an American tradition and one that my family adheres to. Usually the oldest male of each family present (and I have had the honor on a few occasions) invites the bride and groom to come up to the front of the room during the reception ( we've usually done it just before the first dance). If both have Scots heritage we take a piece or tartan for each family and wrap it around their hands, if not we just use our Buchanan tartan. We make up what we say on the spot but it usually goes the effect of welcoming each into the other's family. The brides on our side almost always wear a Buchanan tartan sash at the reception - not at the marriage ceremony - so she will also "pin the tartan", usually a piece of Buchanan tartan ribbon on the groom and we welcome him into our clan. We don't pretend that this is done in Scotland - as I'm not sure it ever has been. But I do know of other families who make a similar nod to our Scots heritage here in the US. So make it your own and do whatever you feel is appropriate to your family. I will try and post photos later from one of our weddings.

Note: We do not use the term "plaid" to describe this. If anything we call it "pinning the tartan".
Although it predates the idea of family tartans, you are describing handfasting, it's a commomlaw marriage tradition that goes back hundreds of years in Scotland and other Celtic cultures. It sort of petered out in the 20th century, but is making a comeback in both traditional and non-traditional wedding ceremonies. I've presided over a few handfastings myself.

That being said, I'm still pretty sure "plaiding" consists of yelling plaid at somebody....

http://www.youtube.com/watch?v=se-Lm...feature=relmfu