PDF Export - White Lines Around Text/Images

[Sketch_]

Hi,

I am having a problem with a book cover PDF export from Affinity Designer.

The PDF (for print) export looks great when opened in Mac Preview, however, when uploaded to Amazon KDP the thumbnail image has white box lines around the text/images (screenshot attached).

Any idea as to why this is happening and steps I can take to resolve the problem would be much appreciated.

[stokerg]

Hi @Sketch_and Welcome to the Forums,

Which PDF Preset did you use when exporting?

From looking the PDF spec for KDP, they prefer PDF/X-1a:2003 so can you try exporting with that selected, if you haven't already and see if you have the same issue.

[Sketch_]

Hi Stokerg,

Thanks for the reply.

I exported using File > Export > PDF (for print). I didn't adjust any settings in the 'More' options.

Does the PDF/X-1a:2003 'flatten' all layers in the project, similar to 'FLATTEN IMAGE' in Photoshop, merging all visible layers?

I tried the File > Export > PDF (flatten) option, but the quality wasn't that great.

I have previously uploaded 'flattened' Photoshop PDF files to KDP with no problems.