Glass Wall

Glass Walls are a addition in the 1.1 patch. They are a mostly transparent wall decorative item, and resemble Glass blocks. In any other update before 1.1, Glass was placed like any block would be placed, and it didn't have a way to be placed in the background. Before Glass Walls were introduced, you could make holes in the background of your Home, but the size of those were limited. If they were too big, you couldn't sleep, and it wouldn't be suitable for an NPC, because one of the needs for a house is to have a back wall. Now, with the addition of Glass Walls, it is possible to make holes larger, and they can produce safer, natural light.