Invisible Tile

Invisible Tile is a decorative block that is completely invisible (it looks as if there isn't any block in the location where it was placed). You can walk or build on top of it.

Despite looking like thin air, Invisible Tile is very sturdy: it has 50 hitpoints (second only to the Diamond Block, which has 84). This can be useful for protection against harmful weather.

Caveats

 * When placed, this block won't appear to be completely invisible, but it immediately turns invisible if you Paint it (with Paint Mode of your Matter Manipulator), regardless of which color you use.
 * Being invisible means that this block shows background of the current biome. If you place it in the ocean, it won't show the ocean liquid, and therefore wouldn't be completely invisible.