An artist just emailed me a question about shipping her acrylic paintings, highly textured, and large sized (5’ x 8’) from California to India, and wanted to save costs by shipping them unstretched rolled in tubes.
Rolling and shipping in tubes will not hurt the paintings, but its best if you don’t fold them. Since her shortest measurement was 5’, here was my advice:
(1) take all the paintings off the stretchers, and place one on top of the other using plastic in between them. DO NOT use glycine as that will stick to acrylic (not to oil and that's why shippers often mistakenly use it on acrylic) and do not use wax paper. The best plastic to use are the rolls of painter's plastic (its officially called HDPE plastic but often is not labeled like that) you find in home improvement stores. The plastic is usually cloudy whitish - not clear - and comes in thicknesses like 4 ml or 6 ml. You can use any thickness, but probably a 3 or 4 ml is best. Stack the canvases so that the painted side faces down towards the floor. You can also use garbage bags, cutting them at their edges to create a big sheet of plastic from them.
(2) Get 2 cardboard mailing tubes - one that is larger than 5' and is very wide in diameter - probably something around 12" or more. This will be the outer mailing tube. Then get another tube that is 5 ' in length but narrower in diameter, probably around 6" in diameter. This will be your inner tube. Place the inner tube on top of the stack of canvases which are now facing the floor, near to an edge. Now roll the canvases altogether around this "inner" tube so that the painted images are facing outwards from the tube. There should already be plastic between each of the images. Once they are all one big roll, wrap it all in plastic and tape it closed. Place this into the larger outer mailing tube.
Tip: If you just buy the inner tube first, then roll your canvases around it, you can measure the final diameter to make sure your outer tube is the right size.
Another tip: Measurements are different between the US and India. If you plan to restretch the canvases when you arrive there, you may not be able to purchase stretchers the correct size. You can either hang the canvases tapestry style without stretcher bars, or you will have to ship another tube with just the stretcher bars. If you plan well, measure ahead of time, and can get hold of very wide shipping tubes, you may be able to pack the stretcher bars inside the inner tube.
And another tip: If you need to fold them because you can't ship a 5' tube, then fold them around some bubble wrap so that the fold isn't pressed down creating an indent. Make sure the bubble wrap is on the back not the front of the image, or you may get bubble impressions on your paintings.