[Conker]

I'm just curious what people use to back their targets when plinking indoors.

Considering the ridiculously small size of my appartement, I don't want a 1-ft deep and 5-ft high (I use NATO targets) carboard box. Not only would it take a lot of space when stored, I also don't want to reduce the shooting distance which is already pretty short at a maximum of approx seven meters.

But, just having a wood plank or similar also isn't an option as BBs would bounce everywhere.

So... what do you guys do? I already tried some things but I'm sure people have ingenious solutions.