How To Store Books In Boxes. Use a bookend to keep books upright or lay a few books horizontally to keep the books from tipping over. Don’t pack books too loosely, either as movement during transit could put dents and bumps into them.
Books that are longer than eighteen inches or deeper than three inches—such as atlases and maps —should lie flat, and can be stacked in groups of three on bookshelves or in storage containers. Place books in the storage boxes horizontally so the spines are kept safe from damage. Books can also be stored upright with the paper edge facing upwards.
I found them in the kitchen plastics aisle of my local blue and yellow big box store for about $2.
Keep the storage boxes out of direct sunlight and away from radiators or heating vents, as the increased temperature can crack bindings. You should also avoid secondhand boxes that were used to carry items with pungent odors. Good circulation of dry air is good for books. At least it will provide an extra barrier to pests.