Well,
As you already know, the chemical/physical interaction may damage the prints and the rate of that will vary based on the actual materials/compounds used on the tube.
One day a client forgot a newspaper on our studio and I left it over a printed test strip on our table through the weekend. On monday I was shocked to see that the part of the paper (Hahnemühle Photo Rag 308) that was touching the newspaper became yellow. The rest of the paper was white as usual.
The use of a physical barrier (paper/mylar/clearbags) may prevent the damage caused by direct contact, but some vapors from chemicals/glues used on the tube may create a hostile atmosphere inside the tube that those barriers will not be able to block.
Surely the best option would be to store the prints flat in clearbags and place them on the tube just for shipping, but that may not be a viable option to you.
Regards.
