If you are exporting an image for a printing proof in the same way you would’ve done when sending images to a traditional commercial printer, then the trim lines may be causing an issue:
Avoid having any printer's marks in your PDF by ensuring your image export settings do not include them.
Traditional printers use trim lines as guides for manual trimming, so they know where the cuts should be made. The color bar along the top serves as a standard color reference to determine whether the content’s coloring is rendering correctly.
You should not send these trim marks or color bars to Lob’s API, as our production facilities have several QA standards in place to ensure cuts are made appropriately and the color is conformant. Therefore, any content that is uploaded in the API request is interpreted as being part of the design, and these trim lines and color bars may be what is causing the error.
To remove these items from your exported artwork, go to your Settings and untick all Printer’s Marks.
Please note that whether or not you should export with “Bleed” will depend on how you built your template.
For example, for a 4” x 6” postcard:
- If you already manually added the bleed (e.g. 4.25” x 6.25” artboard) then the Bleed should be unticked in your export settings
- However, if your artboard was designed without the bleed metrics included (e.g., 4” x 6” artboard), then you should export with the bleed ticked (e.g. 0.125” on all sides) so that the final exported art is the right size (e.g., 4.25” x 6.25”)