I thought you would also admire this beauty. It's a Pierre Cardin, size 4x. The back of the shirt measures 27" long x 33.5" wide.
And what about this!! A muu-muu like 5x, with an even bigger back - 28.5" long x 34.5" wide. Now that is some thrifty yardage. And yes, both were half-price and are 100% cotton.