Question: How big should the entire shelf unit be when making easy cardboard shelves?
Option 0: Each unit should be built at most 2 inches wide. The height can vary somewhat depending on your needs, but 42 inches high makes the it stable and sturdy.
Option 1: Each unit should be built at most 20 inches wide. The height can vary somewhat depending on your needs, but 42 inches high makes the it stable and sturdy.
Answer: 1