As mentioned previously, thin lead sheets (called “lead screens”) are typically placed
on both sides of the radiographic film during the exposure (the film is placed between
the lead screens and inserted inside the cassette). Lead screens in the thickness range
of 0.1 to 0.4 mm typically reduce scatter radiation at energy levels below 150 kV.
Above this energy level, they will emit electrons to provide more exposure of the film,
thus increasing the density and contrast of the radiograph.