Laser pre-print paper properties
Where a good offset paper would have a Relative Humidity of 50% ±10%, laser pre-print papers have a Relative Humidity of 35% ±5%. This is to prevent the paper curling and buckling when it passes through the laser printer fuser unit. Too high a moisture content can also prevent toner fusing to the surface of the paper. Results from high speed laser printers are particularly affected by the Relative Humidity of the paper.