All of the following factors increases the density of X-ray except:
Factors that increase the density of X-ray:

Increasing the mA, KVp or exposure time increases the density.
Reducing the distance between focal spot and films also increases film density.
Density is inversely proportional to subject thickness and subject density due to beam attenuation.
Increasing the kVp
Reducing the distance between focal spot and film
Decreasing the mA
None of the above