I have done this before and was apparently lucky the other times..... THIS time, I was getting a Blue-shifted glare on the outer edges of the paintings. The setup: Black Muslin tacked on a wall with the Paintings hung on the wall. I had two monolights. I tried bare reflectors, Umbrellas, Shoot-Through Umbrellas. All were pretty much doing the same thing. Getting the lights far away at very oblique angles (20-25 degrees) improved it but didn't fix it. I was aiming the lights at the opposite edges of the painting to feather them. Another position that looked ridiculous but almost worked was aiming the lights basically straight at each other (GOT to have a good lens hood). Finally, I tried bare-bulb and moving the lights even farther away (around 8' or so). I also added a 3rd Barebulb sitting behind me and basically bouncing from the ceiling (luckily the walls were white). I'll have to pick up some Polarizing gels the next time I have to do this.