The doors have been taped shut with foam bumpers and 
paper strips to prevent tape adhesive from damaging the finish.

Shipping artwork is a little nerve wracking.  Here's what I've done to prepare the St. Mark's triptych for FedEx transport.

A plastic vapor barrier protects against moisture.
I detached and wrapped the arch separately.  It nests nicely for
a more compact package.  Cardboard corner bumpers protect
vulnerable woodwork.
1/2 inch bubble wrap floats the whole piece on a layer of air
inside the carton.  
The carton is custom built for a snug fit.  
1st layer of carboard.

2nd layer of cardboard provides additional
rigidity and puncture resistance.
See more artwork from Jason Jaspersen at jjjaspersen.com, and on social networks such as Facebook, Twitter, and LinkedIn.