Layout PDF background not transparent on export. SOLVED

I’m stitching together two PDF surveys in Layout. In the Layout window display the backgrounds are transparent and the two files mesh well. When I export to PDF from layout the layer on top has a white background. I have tried setting the fill to a transparent color and keeping the fill off, both have the same result. Any tricks?

In Layout:

Exported from Layout as PDF

Your profile says mac, it made me think of this bug from earlier

Turns out on mac, layout won’t export certain fills properly in pdf. It seems to have issues with transparency

your case might be related

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Does this apply to both of your imported PDFs, if you change the stacking order?

If the original PDF files are vector data, converting them to DWG/DXF would circumvent the issue. The PDF importer in MAC rasterizes the imported file, and perhaps the background is added at that stage, so another thing to try might be exporting the PDF to a PNG image from a PDF editor and, if necessary, removing the background in a photo editor. It is not bombproof as errors in object stacking and transparency are common in PDF files out of CAD applications.

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wait what ? that’s the whole point of exporting plans as PDFs, having vector plans.
I tried, indeed it flattens the file (same way photoshop would, raster it all on a white bg)
Importing an eps file works well though. You may circumvent the issue by converting the pdf into eps aswell.


(eps on the left, pdf on the right. i find it astonishing that LO rasterises vector PDFs.)

Yes this did happen with either of the PDF imports, depending on the stacking order the one on top covered the other.
After some more playing around I have got a clean PDF export that matches the Layout display window by turning off “Use JPEG Compression for Images” in the PDF export options.

image_2022-11-11_101841385

Aaah… Of course… JPG images don’t support transparency. The exporter doesn’t combine multiple raster images on the page but keeps them separate. I guess that if the PDF is opened in Illustrator or Inkscape, the page still has multiple images on it.

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I think you’ve got it. I had assumed the exporter was flattening and merging the whole image, but it appears not to which accounts for the backgrounds of individual JPEGs within the PDF.:+1:

well, as we say here, I’ll go to sleep a little less dumb tonight.
But it seems logical now you mention it, since LO rasterises pdfs.

I checked in illustrator, the rasterised plan appears as a 270 dpi incorporated image WITH transparence.
On my earlier try, it was the same without transparency.
Solved indeed.

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I have bitter experience from CAD applications that when a PDF page becomes too complex with stacked raster images and vector lines etc. it might finally refuse to print or display correctly. My workaround is to export the PDF page to an image at high resolution, and to recreate the PDF page from that. It might even increase file size but the result is a page that can be displayed and printed.

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