I get mine from staples since the ink I take back pays for them there 22''18''12 they are medium in strength so I used a few loops of packing tape I load usually 40-60lbs since some of the boards are odd shapes at time I like these boxes and through usps I thought I was doing alright its between $28 and highest at 61.8lbs was $37.23 to ship to ewasted maybe I can do better though