Here's a look at Book's clerical shirt.
More pictures after the break...
First, we have a few promo pictures, like the one above.
Now, he wears this shirt in practically every episode, but sometimes with outerwear, which will be in a different post. These screencaps are when he is wearing the shirt by itself.
One of the few times he is wearing short sleeves.
The Train Job:
Our Mrs. Reynolds:
Heart of Gold:
Objects in Space:
My Photobucket Album for Book.
Serenifly Costumes site for Book.