1) Ensure 0.125" total bleed all around (0.0625" for each side is required) and all important type and image is within the safe margin (0.0625" from the cut line) More details.

2) All images must be cmyk at 300 dpi. More details.

3) Embed or outline all fonts. More details.

4) Job must be uploaded it as one file - for 2 sided jobs, merge the sides together to upload the job as one PDF, two different pages. More details.

5) Orientation of the file should be head to head. More details.

6) Black type should be 100K (C0, M0, Y0, K100) More details.

7) Make high res PDF from your working file. More details.