The sweatshirt isn’t just a nod to her alma mater, but also to her late mother-in-law, Princess Diana, who famously stepped out in a Northwestern crewneck after visiting the university in 1996.

We all have that favorite sweatshirt or old T-shirt that we throw on when we want to be comfortable. Maybe it's a cozy fit from your alma mater or a loungewear set that helps you unwind after a ...