Travelling with your flip charts is not as difficult as you might think.
First, cut the cardboard spine off the back. Roll the flip chart up with the front facing outward. Start from the top, not the bottom. If you roll it up facing inward, you might have “split ends” when you hang your chart on the stand.
Second, buy a waterproof quiver in plastic or vinyl. You can usually find them at an arts and craft store. Drop the flip chart into the quiver and give the quiver a shake so the flip chart can unfurl as much as possible.
Seal the quiver with whatever locking mechanism it has. Adjust the sling, and throw it over your shoulder.
Now you’re ready to travel.