From Terry’s blog:
So, our heroes return home.
Beaten, ragged, and yet triumphant. We needed to see that in their costumes. Claire wrapped in Jamie’s plaid, proud and strong. Jamie returning to his family home, vulnerable, but now a man, no longer a boy.
Jamie in trews. I think I have received more comments about this than any other costume. No maybe it is neck and back with why the wedding gown is so low cut. But people want to know why Jamie is in trews.
It is not the first time he has worn them, but it does have significance in this episode. He did throw his cloak around Claire after the trial, but he couldn’t have known he was going to need to do that. The trews are there because we needed to do some character development. Jamie has had essentially the same costume throughout most of the series. Now we are seeing a different side of him. He is now a married man, and as we find out, a man of substance. A Laird.
Trews were worn most often by men who had the means to own a horse. It was more comfortable, for obvious reasons. We’ll see his kilt again, and again. But we need to add dimension, shadow, nuance to him, and to all of our characters as they develop over the years. Even Clark Kent had two costumes to show two sides of his character.
Same thing with the coat. I thought of putting the coat on both Brian (Jamie’s father) and Jamie, as a way of showing how important his father was to him. And when Jamie returns to Lallybroch he can literally “assume the mantle. It is the kind of character development/storytelling that I love to do. It is a small “beat”, but like Claire wrapped in Jamie’s plaid, it add dimension and depth, and helps us to “feel” the story.
See the blog post here