Background Painting Idea - Windows!

[rnanfito]

I am going to paint the back and sides of an in-wall 180G tank, and I have an idea. I'd like to leave a few "viewing portholes" in the back, so I can peek at what's going on BEHIND the live rock wall. I plan to mask off a few 2"H x 6"W window slots, then paint with dk. blue spray paint. I'll make sure to place them where they will be blocked from the front view by rock wall. I may even rig cover plates with a hinged mechanism so I can close the window off when not viewing.
I think it's a good idea - any thoughts? Has anyone else done this?

 

[robchuck]

That sounds like a fantastic idea! Kind of like Rowan & Martin's "Laugh In", but with fish!
I am also about to start work on an inwall setup, and my plan is to cut some black fabric to fit the back of the tank and use velcro to keep it in place. To those worried about salt creep, the tank will be made of acrylic with a top brace, and won't have plumbing or anything on the back side, so I don't anticipate any salt creep issues. Plus, the fabric can be removed to reveal the entire back side of the reef.