We ship aerospace parts. No matter what box you use buy four of them. Cut two of the boxes up and line the assembled boxes with the cut up cardboard pieces. You will in essence be building a double walled box. Much better and stronger. Double tape all the sides/corners of the assembled boxes on the outside.
Using the methods noted above, you should be in good shape.
Good luck, John
Using the methods noted above, you should be in good shape.
Good luck, John