Minecraft wiki entry for Cartography_Table, associated text: Zooming out a map always starts with an existing map, not a blank map. Zooming it out makes the map aligned to the grid that would include the area of the original map. To build a set of maps such as for a map wall, a player cannot create several level 0 (base) maps at one location then zoom them out before going out into the world to fill them in; the player must start with a base map created in each area to be covered by the zoomed out map. See more discussion of map alignment at Map.