Always wondered - time to ask

[NeightRG]

There's an image that's always fascinated me, I know it's popped up here a time or two. This one, from the book "Windsor Style" -



What gets me is the Royal Stewart tartan up front - what a huge sett!

Not to knock the Royal Stewart tartan - I made a kilt out of it for myself and wear it regularly - but it's always been a bit loud for my taste, with it's bright colours and relatively small repeat. But this large sett has such elegance.

Is there a name for extra large sett tartan like this?