Rough fitting of the overflow cup in place. I tried to make the top of the overflow flush with the bottom of the trim of the tank, that way the waterline should be above the trim.
I'm sure Michaelangelo didn't have to pretape his work, but I'm going to go out on a limb and guess he never siliconed in an overflow into an aquarium..
And some black eggcrate, and now just need to let the silicone cure..
I went with black eggcrate because I thought, that combined with the smoked glass, would look really keen. In retrospect I might have gone with thicker glass and that might have been less translucent. Oh well.
Also in retrospect, black eggcrate is expensive ($15/sheet) and hard to find. If I ever run out and need more, I'll just use white and use that Krylon Fusion spray paint.