This is how to ship stretched canvas’s and framed paintings, assuming that your buyer doesn’t want to, or have the knowledge to restretch or frame the work themselves. I have shipped dozens of works and will share my favorite ways.
The cheapest way to ship art is to put in it a plastic trash bag to keep it water proof, cover the surface with bubble wrap or padding, then add more padding, then make your own box to fit out of cardboard. Cheap but cumbersome and time consuming.
The easiest way is to pay Fed Ex or UPS to wrap and ship it for you, pricy but if you are in a rush and the buyer is willing to pay, go for it.
The way I prefer to ship is using one of Fed Ex’s new painting or poster boxes. The Painting box has an insert with a plastic envelope attached and it literally holds your work suspended in the center of the box. This box works great for work 18×20 through 36×48, and will work for stretched canvas and works framed behind glass. The poster box is about two inches think and will work great for lightweight canvas (I still would use the white trashbag wrap underneath) or works on panel. I buy the box, take it home and pack it and don’t have to pay the “packing Fees” which are more then what seems reasonable for something they do in about two minutes. I then take the box back to fed ex but you could ship it your preferred method.
The photo is of two paneled works in the insert of one Medium size frame box. When I pack them for shipping I actually put them face down against the cardboard because I feel its a stronger surface for the actually canvas.