pdfscale custom resize appears to generate different flavor of pdf that interferes with gs PDFX (?)

That is interesting. The GS calls look pretty much identical. Weird.

EDIT: I though you had the pdfScale GS calls there, but now I am not sure.
Are those GS calls from pdfScale?
If not, can you run both calls with -v --print-gs-call for us to compare both calls and the verbose info?

I made some tests here and the GS calls seems identical, just with Width X Height changed.

Paper std 11x17

$ ./pdfScale.sh --print-gs-call -v -r 11x17 mint.pdf
pdfScale.sh v2.6.1 - Verbose Execution
   Single Task: Resize PDF Paper
       Dry-Run: FALSE
    Input File: mint.pdf
   Output File: mint.11X17.pdf
 Get Page Size: Adaptive Enabled
        Method: Grep
  Source Width: 596 postscript-points
 Source Height: 843 postscript-points
    Print Mode: Print ( auto/empty )
  Scale Factor: Disabled (resize only)
   Fit To Page: Enabled (default)
   Auto Rotate: PageByPage
   Flip Detect: No change needed
  Run Resizing: 11X17 ( 792 x 1224 ) pts
  Final Status: File created successfully
[GS RESIZE CALL STARTS]
"/usr/bin/gs" -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dSAFER -dCompatibilityLevel="1.5" -dPDFSETTINGS="/printer" -dColorImageResolution=300 -dGrayImageResolution=300 -dColorImageDownsampleType="/Bicubic" -dGrayImageDownsampleType="/Bicubic" -dColorConversionStrategy=/LeaveColorUnchanged -dSubsetFonts=true -dEmbedAllFonts=true -dDEVICEWIDTHPOINTS=792 -dDEVICEHEIGHTPOINTS=1224 -dAutoRotatePages=/PageByPage -dFIXEDMEDIA -dPDFFitPage   -sOutputFile="mint.11X17.pdf" -c "" -f "mint.pdf"
[GS RESIZE CALL ENDS]

Paper custom in 15 10

$ ./pdfScale.sh --print-gs-call -v -r 'custom in 15 10' mint.pdf
pdfScale.sh v2.6.1 - Verbose Execution
   Single Task: Resize PDF Paper
       Dry-Run: FALSE
    Input File: mint.pdf
   Output File: mint.CUSTOM.pdf
 Get Page Size: Adaptive Enabled
        Method: Grep
  Source Width: 596 postscript-points
 Source Height: 843 postscript-points
    Print Mode: Print ( auto/empty )
  Scale Factor: Disabled (resize only)
   Fit To Page: Enabled (default)
   Auto Rotate: PageByPage
   Flip Detect: Wrong orientation detected!
                Inverting Width <-> Height
  Run Resizing: CUSTOM ( 720 x 1080 ) pts
  Final Status: File created successfully
[GS RESIZE CALL STARTS]
"/usr/bin/gs" -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dSAFER -dCompatibilityLevel="1.5" -dPDFSETTINGS="/printer" -dColorImageResolution=300 -dGrayImageResolution=300 -dColorImageDownsampleType="/Bicubic" -dGrayImageDownsampleType="/Bicubic" -dColorConversionStrategy=/LeaveColorUnchanged -dSubsetFonts=true -dEmbedAllFonts=true -dDEVICEWIDTHPOINTS=720 -dDEVICEHEIGHTPOINTS=1080 -dAutoRotatePages=/PageByPage -dFIXEDMEDIA -dPDFFitPage   -sOutputFile="mint.CUSTOM.pdf" -c "" -f "mint.pdf"

Comparing

"/usr/bin/gs" -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dSAFER -dCompatibilityLevel="1.5" -dPDFSETTINGS="/printer" -dColorImageResolution=300 -dGrayImageResolution=300 -dColorImageDownsampleType="/Bicubic" -dGrayImageDownsampleType="/Bicubic" -dColorConversionStrategy=/LeaveColorUnchanged -dSubsetFonts=true -dEmbedAllFonts=true -dDEVICEWIDTHPOINTS=792 -dDEVICEHEIGHTPOINTS=1224 -dAutoRotatePages=/PageByPage -dFIXEDMEDIA -dPDFFitPage   -sOutputFile="mint.11X17.pdf" -c "" -f "mint.pdf"
"/usr/bin/gs" -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dSAFER -dCompatibilityLevel="1.5" -dPDFSETTINGS="/printer" -dColorImageResolution=300 -dGrayImageResolution=300 -dColorImageDownsampleType="/Bicubic" -dGrayImageDownsampleType="/Bicubic" -dColorConversionStrategy=/LeaveColorUnchanged -dSubsetFonts=true -dEmbedAllFonts=true -dDEVICEWIDTHPOINTS=720 -dDEVICEHEIGHTPOINTS=1080 -dAutoRotatePages=/PageByPage -dFIXEDMEDIA -dPDFFitPage   -sOutputFile="mint.CUSTOM.pdf" -c "" -f "mint.pdf"

So, identical calls, just with different sizes in points.

While looking at the verbose info, I noticed that the custom call actually inverted the orientation and caused the script to invert the Width X Height. Not sure if that is relevant, but it is a difference.

   Auto Rotate: PageByPage
   Flip Detect: Wrong orientation detected!
                Inverting Width <-> Height

You can disable flip-detection with -f d. But this only inverts the values of Width and Height and nothing else.

You can also mess with the auto-rotation options to see if it helps.

tavinus / pdfScale

pdfscale custom resize appears to generate different flavor of pdf that interferes with gs PDFX (?) #47

For some reason, I've encountered an issue where pdf's scaled using 'custom' page size don't seem to allow post-application of PDFX items, while when I use a standard 11x17 size, it does!?":

^^ inspection of such version ^^ with pdfinfo -f 1 -l 1 -box gs-converted-pdfT.pdf shows boxes have been updated

^^ inspection of such version ^^ with pdfinfo -f 1 -l 1 -box gs-converted-pdfM.pdf shows boxes are all still equal to MediaBox