When people speak of an unconstructed linen sports coat, do they mean it has absolutely no lining--including the sleeves? Unlined is unlined. Unconstructed is well. If you remove the lining from most RTW jackets you'll find the inside isn't that pretty. A unlined jacket needs to be prettied up so the seams look nice. With a lining all those guts are covered. Maybe rip a seam and take a look at how well finished it is under the lining.