To transfer paper from standard storage to the print area for a few hours or days before printing. Conditioning ensures that the paper’s moisture level and the temperature is the same as in the print shop. Low paper humidity can cause:
Shrinking of the sheets’ edges that cause the paper to swell in the middle, distorting the image, known as curl. Static buildup can slow down the print run.
The paper can become brittle, causing it to crack.
More dust that causes pinpricks on the printed sheets.
High humidity causes the sheets to become wavy and not flat and drying time will be longer.
If the sheet swell or shrink it’s impossible to condition them back to their original, printable dimensions.