The bloodstone backdrop gives an exclusive and shadowy look to your structure. With its very dark green-black color, this is by far the darkest of all backdrops.
How to Obtain
Bloodstone backdrop blocks can be crafted from bloodstone ore, which can be mined only in hellish biomes. Many a Deepworld miner has perished while obtaining this ore. One bloodstone ore will craft three backdrops. This block can also be mined directly from many generated surface buildings, bunkers, and dungeons in hell worlds. You can also trade for it in a market world.
Since it's difficult to distinguish this background block from its solid form (bloodstone brick), the two are often used together to create mazes and dungeons that are fiendishly hard to navigate.
When bloodstone blocks were first implemented, there was a bug that returned bloodstone ore to your inventory when you mined a bloodstone backdrop block. Since one bloodstone ore can be turned into three crafted blocks, this meant you could accrue infinite bloodstone (and thus craft infinite bloodstone items) from one bloodstone ore.