Oh yeah, material.
I used “matte gloss” photo paper. Gloss for colour vibrance but not glossy gloss or premium gloss due to reflections being annoying in gameplay. It might also be called “satin gloss”.
Wouldn’t bother putting it on nice big wooden board and frame that kind of thing.
I would reserve that for really nicely done maps based on detailed real world map for example.
Like cccasionally the continent lines hurt my eyes. So I wouldn’t bother spending $150 or something.