Background walls



Background walls are tiles that create backgrounds. Most wall types are items that can exist in player inventories, and can be placed by players in any area that doesn't already have background walls. Walls can be removed with a hammer. All walls fall under two categories:


 * Housing walls are placed by players or generated in certain structures. They prevent enemies from spawning, but do not do anything to prevent their passage, and a mostly unbroken background of housing wall tiles is necessary for a structure to qualify as a house for attracting NPCs, or to place a Bed that can set a player's spawn point.
 * Natural walls are instead found throughout the world in several biomes, and cannot be placed by players. Most natural walls are able to be crafted and placed by players. Natural walls will not stop enemies from spawning, and cannot be utilized for houses, but natural walls made by players act like normal walls. These walls must be removed by starting from their edge (i.e., there must be at least one adjacent tile with no wall or housing wall), unlike housing walls, which can be removed from any point.  can remove all natural walls within their blast radius as long as an edge is somewhere within the radius.

Certain walls, such as Obsidian Brick Walls or Dungeon Brick Walls exist in both natural and housing forms. With these walls, the player must break the natural walls and replace them in order to allow them to count as housing walls. Furthermore, the natural form of some walls, such as Dirt Walls or Jungle Walls cannot be harvested, and must instead be crafted or purchased from an NPC.

Walls are generally obtained via crafting, purchasing from NPCs, or harvesting certain naturally-generated walls. One item of crafting material generally crafts four of its corresponding wall items. Most walls can also be crafted back into the items they were made from (four walls to one item), except for any wall crafted from more than one ingredient (e.g., Stained Glass).

Crafted walls
These walls are made by the player using various crafting materials.

Purchased walls
These walls are purchased from various NPCs.

Harvested walls
These walls can be harvested in various places when exploring the world. Most of them can also be obtained through crafting.

Converted walls
These walls are normally created by biome spread. They can also be made using Solution sprayed with the Clentaminator, and on the they can also be crafted or purchased (with the exception of the natural Mushroom Wall). On the the Clentaminator is the only way the player can make these walls.