poita said:
I have also seen IB prints where the masking area is darker, especially where a print played at one cinema for a long time, the projected area has lightened compared to the area that stayed behind the gate-mask.
But anyway, most well preserved IB prints look fantastic, if a little contrasty and have great colour.
That can possibly be attributed to arc burn maybe? I've seen the same thing on some old 50's drive in prints in the past.