There are two ways to apply printed graphics to a box or package; direct or sheet. Direct printing is when the box is printed on directly from the press, whereas sheet printing is the act of printing on paper and using an adhesive to affix the sheet to the box.
There are five printing processes to consider when printing on packaging: Offset Lithography, Flexography, Letterpress, Screen and Digital. Each process has parameters which help you identify the right process for your project.
Offset Lithography– best used for complicated graphics and four color photography
Flexography– depends on the absorbency of the material printed upon
Letterpress– best for simple markings and strong color
Screen Printing– works well for combined board printing and does not crush flutes
Digital– cost effective for short runs and variable data printing
Another way to help you decide which process is right for you is to examine the line screen. The higher the line screen, the more polished the graphics.
|Screen and Line Parameters||Lines per Inch (LPI)|
|Offset Lithography (sheet)||150-300|
|Offset Lithography (direct)||150|
|Letterpress||85 or less (coarse)|