I have a printed (black) graphic T Shirt (white) where the design has held up very well over the years. When I moved all my clothing to my new place, I noticed that many of my shirts (button up blends, cotton white t shirts, etc) started turning yellow in my new location. And when I say discolored/yellow, I mean the entire shirt(s).
(I added some white pants, an envelope, and a black/white striped scarf, for comparison.)
Maybe it was the different minerals in the tap water or that I left my closet light on all the time or something else... I have no idea.
How can I get this shirt to be whiter without screwing up the design?