In the printing process, as well as the hygroscopic variations in the paper,
the problem of electrostatic discharges may also arise. The solvents contained
in the printing presses may catch fire if the electrostatic discharges inflame
the vapour. In addition, the printing presses may generate electrostatic charges
when driving the paper (a newspaper press may generate up to 2,000,000 volts
when driving the paper).
