Heat is generated from roller friction and builds up in the roller train. The newer high-speed presses are especially prone to heat buildup. The water-cooled oscillators remove excess heat and help keep the rollers at a consistent temperature. A change of one degree Fahrenheit will alter the ink viscosity by 3-4%. A 50% reduction in ink viscosity could occur with a temperature increase of just 12.5@ F, which is not uncommon on printing presses. Keeping the ink rollers at a consistent temperature helps maintain stable ink/water balance and steady printing conditions. Changes in ink viscosity effect ink tack, wet trapping, ink misting, and water pickup.