Actually, you should NEVER, EVER pin both the top and bottom aprons together - no matter how windy it might be! To do so is to court disaster. I have seen some dreadfully ripped kilts over the years where this has been done by guys who knew no better, and either the top apron or the pin itself was snagged on something in passing. Result: a torn kilt.

The average kilt pin is not heavy enough nowadays to act as a weight. If the wind is going to lift an apron it will do so whether you have a kilt pin or not. In this day and age, when many pins are made from light alloy or a metalised plastic, they are not much more than decorative. Several of mine are made from solid silver, but they are still not what one would call 'heavy'.