I developed this "system" a couple of decades ago when I flew to shows regularly. I picked up a couple of large hard shell thrift store suitcases and ordered a supply of 4 inch cube boxes. The boxes fit so perfectly that they could not compress while in transit. I wrapped each insulator in a couple of pieces of newspaper, enough to fit one piece in each box snuggly. I used a single piece of cardboard over the open top of the boxes and used a foam sheet to take up any head space between the boxes and lid of the case. I never had a single piece damaged using this technique.

The greatest expense was for the boxes which cost over a buck a piece twenty or so years ago.

I still have two of them left I'd sell for cheap if you can pick them up...to 'spensive to ship!