Here is how I ship a painting:
- Painting is wrapped so it will make it safely to Fedex
- Buy an Industrial shipping box lined with kevlar and three layers of foam
- Perforated foam cut to the size of the painting
- Foam overlay on top between the kevlar
- Tape box and pay for insurance
I learned how to do this the hard way. There is nothing more terrible for an artist than having his work damaged.