Protecting Wet Paintings
If your paintings are still wet, you can still pack them for shipping. Canvas stretchers have a lip carved into their backs. The lip raises the canvas so that it can be stacked on top of a second painting. The lip will only touch the bottom paint at the very edges so that it can be placed over a wet board.
If you have wet paintings that are on boards they can still be shipped. Cut four 2-inch squares of cardboard. Score the squares from corner to corner and fold over to create four double-thick triangles. Tape the triangles closed. Place the triangles on the bottom painting corners. Begin stacking the paintings, adding more triangles at the corners. Tape the corners securely to the backs of the paintings. If your paintings are very large you can add little strips of double-thick cardboard at the edges. The cardboard keeps them separate.
Place last painting face down. Tape all the paintings together securely and bubble wrap them as one unit.