Okay, so you take parts A and B of SmoothOn's Foam-It 3 1 gallon kit $64 at http://www.farwestmaterials.com - specific page at http://shop2.pageland.com/Item.cfm?StoreID=16&BasketID=ZdOABleGgctFgsD&RefID=&CID=&ItemID=5463&Search=foam

original product developed by SmoothOn, though you can get it for less at FarWest, I think - http://www.smoothon.org - it expands 20x its liquid size.  I found that with the size boxes I'm making, I'll probably get 6 - 8 boxes from one $64 kit.

Take a box and line it with plastic - either a plastic bag as above, or plastic sheeting as below.  This keeps the foam from sticking to the cardboard box (which I still use as an outer protective device - smile).

Take parts A and B and mix part A before you mix the two (follow directions), then mix the two for about 60 seconds.  Then pour around your piece which you will prop up on styrofoam bits in the bottom of the box.  Once you pour, you will see the foam start to expand quickly.   Make sure your piece is totally sealed - I made the mistake of not having a piece sealed and it created an hour or so of repair work, plus I had to break the box to get it out, which was no big deal as I just glued it back together with wood glue.

Once you've gotten the base to where you want it and it's cured, then lay plastic over the piece all the way over the box so that you separate what you have done with what you are going to do, add the lid. 

Once you are done you'll have an extremely strong, rigid box that will completely protect and buffer your piece from impact.  I'll report back to let you all know how this worked for me while traveling.

You can then line the box with satin or something, which I did  - here's my warrior with the bottom half lined with fabric.  He's nestled in there perfectly, with enough support for his sword arm.

More to come when I get back from Indianapolis.