Double boxing is when your item is packed into a box and this box is put into a larger box to allow for empty spaces around the first box. Double boxing drastically reduces the chances of your items being damaged during shipment. The larger outer box is usually a minimum of two inches larger than the inner box on all six sides: top, bottom and four sides. The outer box can have more than two inches of padding but the 'textbook' definition of double boxing is at least two inches larger than the inner box. Occasionally a moving company will pack loose items in a box within a box for extra protection in the moving truck.