Sending Adobe files to print can become very complicated, very quickly.
One thing that is important to remember when creating a file that uses images and fonts is that these files are not self-contained.
The images placed in InDesign and Illustrator files are actually linked to another location on your computer. When sending these files to be printed, InDesign or Illustrator cannot access the same location that the images were linked to on a different computer. Packaging your files creates a folder on your desktop that bundles your file with all of the linked images and fonts. Once packaged, the file is complete and your printer has all of the elements needed to print your files properly.
To get the process started go to File > Package.
This will bring up a dialog box that gives you all the information about what is going to be packaged. You can go through the other sections below “Summary” to make sure everything is good to go. These tabs show everything that is going to be packaged into the document. Once you have reviewed this information, click “Package”.
After clicking “Continue”, a “Package Publication” window will pop up. Here you will choose a location on your computer to save a folder with all the InDesign/Illustrator file information and fonts and files used within the layout. Navigate to where you want the press-ready folder saved and click “Package”. This will start the packaging process.
*NOTE*- If any warning messages pop-up, indicating missing links or fonts that will not be packaged due to licensing restrictions, your file will be incomplete. Return to your working file and relink missing links or replace restricted fonts. This will resolve these warnings before attempting to package the file again.