So... which plaid is which?

[imrichmond]

The piper's plaid starts at the left shoulder, runs across the back, under the right arm, across the chest and is fastened at the left shoulder so that it hangs down the piper's left side with the fringe about level with the top of the spat (if these are worn). Putting one of these on can be a real pain and is usually easier with the help of a second person.

The fly plaid is a simple rectangle of cloth, usually fringed at both ends, which is attached at the left shoulder so that part of it hangs on the left side of the chest with most of the length hanging down the back. Other than the attachment at the shoulder, the fly plaid hangs loose front and back, hence the name "fly" plaid.