I shipped 6 Thomas Moser dining room chairs (about as expensive as you can get) from NJ to my sister in Seattle. I bought wardrobe boxes from U-Haul and modified them to fit one inside another using Gorilla tape so it was more or less double walled-it was truly a thing of beauty
. The clothes hanging rod inside helped maintain the integrity of the box. I wrapped them in bubblewrap and added padding to the inside of the boxes as well. Despite my best efforts the arm of one of them was broken in transit by Fed-ex and had to be repaired, all the others fared well. Fed ex picked them up at my home. Good luck