To ensure your custom packaging cuts correctly, it is very important that the unique structural dieline we send you is included as part of the print file: click on the dieline layer "dieline - do not print" and click on the toggle menu on the top right and select "Options for "dieline - do not print"". In the Layer Options pop-up, make sure the option Print is checked before proceeding to saving your file to a pdf format.
The structural drawing will contain Spot Colors for the cut and crease lines in the Swatch menu. These colors are used to tell the cutting and creasing machines how to convert your unique product. Do not delete or convert the spot colors into CMYK, and do not delete the dieline layer.
Save your AI file as follows:
Make sure the Adobe PDF format is set to Illustrator Default, with the first option "Preserve Illustrator Editing Capabilities" checked.