At least...
You didn't accidentally shoot the inside wall of your flat!
Luckily, I was using marbalizer and after it dried out we found out that it glows really well under UV. I now have a plan for the decorating of my mixing room (Loads of UV stuff, turntables etc) that involves two markers, four sorts of paint, a tarpaulin and a fan heater.
With any luck, the room will turn out looking quite nice. On the other hand, it could end up looking like several babies have been sick everywhere after eating road marking paint.
I might have to practice on the shed first.
Wookie