When you upload a file to the Canon Webshop, the portal automatically checks the file for technical errors, such as those concerning format, margin, and image resolution. The system also checks whether your file contains bleed and cut marks.
The content of the file is not checked. You will receive a notification in the portal telling you to resolve the errors and submit a new file. If you ignore this message and accept that it contains errors, the file will be printed with the errors included. In such cases, Canon can no longer guarantee the quality.