This shirt looks identical to Dean’s Scruffy Green Shirt (which first appeared in S3), but it is much too light to be the same shirt. It does have the same characteristics though – double shoulder seams, a seam across the back, a seam down the outside of each arm, and pleated front breast pockets. It does up with buttons.
Brand Info: Point Zero
In The End (5x04), Dean wears it for the entire episode.
In The Third Man (6x03), Dean wears it from the beginning of the episode until after the confrontation at Balthazar’s house. He changes out of it for the final scene by the Impala.
In Slash Fiction (7x06), Dean wears this shirt in Rufus’ cabin and on the way to Frank’s house. When they actually get to Frank’s house though, Dean has changed.
In Freaks and Geeks (8x18), this might be the shirt that Dean wears when he goes up to the lodge and finds the vampire, and then accompanies the kids back to the house to discover that Sam’s been tied up and Victor is a douchebag.
In Sharp Teeth (9x12), this MIGHT be the shirt that Dean wears at the end of the episode when saying goodbye to Garth and then trying to talk things out with Sam.