Several blood decals/overlays from some Source games I have, but turned into props.
Personally, I'm using this for video making, since decals sometimes get deleted from brushes when reloading a scene save. This eliminates the issue, by making the blood decal placable and moveable.
I hope this is helpful for scene/videomakers.
Blood decals provided come from Half Life 2, HL: Episode 2, Left 4 Dead 2, Team Fortress 2, Postal 3.
If you would like to send me photos you've made using this addon, please post an imgur link!