Your textbook survives the semester in a paper bag

A paper grocery bag makes a bulletproof book cover for any textbook, and it takes about two minutes.

Cut the bag open along its seams so you have one flat sheet. Lay the book closed on the sheet, leaving about two inches of extra paper on the top, bottom, and sides. Cut out that rectangle. Now wrap it like a gift: fold each side over the book’s edges, then fold the top and bottom over the covers, tucking them inside the front and back boards. Close the book and press the folds flat.

The whole trick to “fits any textbook” is not measuring the spine — it’s making the top and bottom flaps deep enough. If your flap is at least an inch and a half into the cover, the bag will stay put even with heavy use. Tape the flaps lightly if you want, but most bags hold