Flat in printing refers to the state of a printing plate or piece of paper before being fed into a printing press. A printing plate is in “the flat” when not attached to a press cylinder; sheet paper must also be “in the flat” before feeding into it.
A flat can also refer to the final result, such as “the print is flat.” In this context, this refers to prints without depth or dimension, unlike relief and intaglio prints, which include relief patterns.
Flat is a printing term describing the condition of the printing substrate before it is fed into a press. A substrate can be considered flat if its surface is free from ripples, waves, or distortions that could affect print quality.
Maintaining a flat substrate ensures that printed images will not suffer from distortion due to printing. Printing processes could make images smeared or otherwise disfigured if a substrate isn’t level. In some instances, flattening must occur before feeding into a press; in others, some presses have specific mechanisms for flattening substrates.
Once a substrate has been flattened, it must remain this way until fed into a press. Otherwise, its shape could become warped again and require further flattening efforts.
Flatness in printing is essential for several reasons. First, flat ensures your print job will have consistent registration – meaning all colors line up perfectly in multi-color jobs. Second, flatness helps prevent warping and distortion so your finished product looks as intended. Thirdly, printing both sides simplifies life, saving time and money!