An important part of preparing artwork for printing boxes and packaging, is the cut and crease lines.  Cut lines determine where the card will be cut, and crease lines determine where the card will be creased (scored) so it can be folded.
There should be one continuous cut line around the entire artwork, so that the box a clear outline.  It’s important that there are no gaps in cut lines. Extra cut lines can be added for flaps, slits and voids in the box design.
Vector artwork is required to produce cut and crease lines, therefore programs like Adobe Illustrator are best suited.
To create a cut line in Illustrator, first create a custom spot colour named “Cut”. Use the spot colour named “Cut” as a stroke for the lines you want cut, and set the object to “Overprint” in the Attributes palette.  Overprint enables us to use the cut line for cutting, and ignore it for printing.
To create a crease line in Illustrator, do the same and create a custom spot colour named “Crease”, and use it to stroke lines that require creasing. Don’t forget to set all of these special lines to “Overprint” so we won’t print it.