I recently printed a few photos at Walgreens in the size of 20x30. They offer poster paper options of Glossy or Matte. I got the glossy and they look great but since it is a large area, I can see waves in the print when you look at it from different sides. {Maybe because they roll the print into a cylinder to put it in the bag) Should I be printing large sizes like this on some type of poster board or what are the other options?