Explosives are powerful. Maybe a little too powerful for my liking.
I've set up a trap where mobs fall into a pit of explosive proof material (in this case, mythril ore), where I'm free to throw dynamite or bombs to my heart's content.
However, I want there to be a background wall so that mobs won't spawn inside the pit while it's closed off (using active/inactive stone blocks).
So far all my attempts have failed with the background being blown clean off the sky.
Is there a wall that will remain in place even if dynamite goes off right in front of it?