It's Jil. I am mad I never bought one when they were in the stores. Comes in like 4 different colorways and you can check it out on Yoox.com and they have a full size run.
The button down shirts I got are like 52s and they fit me in the way that I like so I would say "true to size". The jackets on the other hand can go from 50-54 (for Jil too) so I wouldn't buy online without getting measurments.
I'm not gonna buy a jacket online without trying. Tshirts and button downs i'd probably consider. I might ask around someone near my size to see if they have any measurements. Maybe email south willard and ask for a measurement on a 46 and 48. The tshirt is a bit rich for my blood but man are those jil shirts nice. I like the lighter more subtle one you got as opposed to the other set of darker ones on yoox.
That shirt is so nice. I remember liking it when you first posted i t. What season was that? Yoox always has shit out of date. I can't afford much jil or anything but man do i like that windowpane/grid/line stuff.