My late grandfather had a map of the Philippines painted on burlap that he acquired during WWII. On that map, the water was not painted and the burlap was obvious. The paint on the islands "webbed" across the fibers, obscuring the texture, but not completely eradicating it. As the map has aged, the paint has come off in many of those areas, but the fibers are still stained with the color.

It's a really neat map--I'll try to remember to take my camera with me and get a shot of it next time I visit my grandmother. If she's still displaying it, that is.

Anyway, this looks much like the painted areas of my grandfather's map must have looked when it was new.