Paintings come in different forms, so packing them can vary a bit. In general, look towards using a mirror carton as your best bet for moving a painting. You’ll want to aim for one that is about 3-4 inches bigger than each side of the painting. This will allow enough room for the proper amount of padding.
One variation is if your painting has a glass cover. No matter how many steps you take there will always be a chance of damage to the glass. That’s why you need to put masking tape on the glass in the shape of an “X”. This will keep the glass in place in the case of damage.
To pack your painting if you don’t have a glass cover, you will want to first wrap the painting completely. This will prevent friction prints in case that the painting moves at all within the box.
Another variation is if you’re moving an oil painting. This type of paint will be damaged if it makes contact with paper, so look toward padding of a different material.
For paintings with frames that you don’t want damaged, you will want to purchase cardboard corner protectors. These corners should be placed over the wrap that you put around the painting.
Finally, once you are ready to put the painting in the box, use wadded newspaper at the bottom. Once it is in, pad it with bubble wrap. Be generous with this step, as more is better than less.