The casewrap, also known as a case cover or hard case (or “undie” on this site!), is the hard casing of a book, the cover you see when you remove the paper dust jacket:

Sometimes the undie is the same image as the dust jacket that covers it, but sometimes they're different, and when the images are different it can mean a few different things: a hint at the story inside, a visual motif or theme for readers to follow within the story, a fun additional cover option, or even a sneaky way to start the story before readers open the book. Undies can leave lots of room for interpretation and conversation!

Scroll down to take a look at some of my favorite undie reveals, and don't forget to check out my other favorites lists: