Affinity Publisher not exporting PDF to correct dimensions

[akcon]

Hi all,

I use Affinity Publisher 2.0.4

I'm making a PDF design for a billboard that is 32feet x 8feet (which is 115200px x 28800px).

I have set up the correct page/spread dimensions for this, but every time I try to export it, it exports to dimensions that are only about 1/4 of the size that it should be.

I'm using the PDF (Print) preset for export.

Why is Affinity publisher not exporting to the correct dimensions that are specified within the document setup?

 

Thank you for any help

Edited June 28, 2023 by akcon

[GarryP]

Welcome to the forums @akcon

300DPI (if I’ve calculated it correctly) seems a bit high to me for a normal printed billboard project.

See: https://streetmediagroup.com/art-specs/
And: https://resources.printhandbook.com/pages/dpi-for-printing.php

I’m not an expert in this area, and one will probably come along soon, but the links I’ve given are probably worth looking at in the meantime, especially the last one.

[akcon]

Thank you very much for the reply and help Garry!

I understand about the DPI being too high, but I'm still confused as to why it would be exporting to the wrong dimensions even if the 300DPI is too high?

 

Thanks again!

[GarryP]

Sorry, I can’t answer that one.

However, I did notice that first link I gave mentioned a 1:4 scale and you said you were getting the output of ¼ size, so that’s an interesting coincidence.

I vaguely remember there being some maximum limit on some PDF document format dimensions, so if you can give us a screenshot showing your export settings that might help someone who’s more knowledgeable.

[akcon]

Sure I've attached the export settings!

Btw the 1:4 export isn't an exact value. It's just approximately 1:4 smaller

 

Thanks again for your help!

[walt.farrell]

4 minutes ago, akcon said:

Btw the 1:4 export isn't an exact value. It's just approximately 1:4 smaller

How are you determining that?

For example, if I make a file of your dimensions, then Export it to PDF from Publisher, then Open the PDF in Publisher, I get a document that is in points, not pixels. Changing it to pixels via Document Setup, the dimensions are correct. As PDF dimensions are generally in points, perhaps whatever you're using is showing that kind of measurement for you?

[akcon]

1 hour ago, walt.farrell said:

How are you determining that?

For example, if I make a file of your dimensions, then Export it to PDF from Publisher, then Open the PDF in Publisher, I get a document that is in points, not pixels. Changing it to pixels via Document Setup, the dimensions are correct. As PDF dimensions are generally in points, perhaps whatever you're using is showing that kind of measurement for you?

Thanks for the reply Walt.

I've just checked and you're correct, the exported PDF file is showing pt instead of px. Though when I bring the exported PDF file back into Affinity and change PT to PX via Document setup, it's still only around half the size  (55296px X 13824px), whereas it's supposed to be 115200px x 28800px

So it's basically exporting at close to half the size it should be for some reason.

 

[walt.farrell]

When I did it, the size was correct after converting to px. Did you tell it to use 300 DPI, or let it estimate?

[akcon]

I let it estimate when importing the PDF to check, as that was the default option.

When I import the PDF and let it estimate it says 27648pt X 6912pt (when I convert this to PX via Document setup it's 55296px X 13824px)

When I import the PDF and select 300DPI it says 27648pt X 6912pt (when I convert this to PX via Document setup it's 115200px X 28800px, which is the correct size I originally exported it at).

So thank you for clearing that up for me, it's good to know that it's actually exporting correctly, but I guess my question would be: why is it exporting to PT rather than PX? I have it set to PX in Document Setup when exporting, so would have figured the exported file would display it's units in px.

My apologies if these are silly questions, as I'm quite new to Affinity.

Thanks again!

 

 

[walt.farrell]

9 minutes ago, akcon said:

why is it exporting to PT rather than PX?

PDF files use points as their measurement units.

[akcon]

1 minute ago, walt.farrell said:

PDF files use points as their measurement units.

Ahh that would be it so!

Thanks again for the help Walt 😁

[Oufti]

8 hours ago, walt.farrell said:

PDF files use points as their measurement units.

And there is normally a maximum size, according to the ISO standard:

Quote

Per the ISO 32000 standard for PDF, the page dimension limit is 14,400 PDF units [i.e. PostScript points, pt] in each direction. A PDF unit is 1/72 of an inch so the limit equates to a maximum page size of  200 x 200 inches. (5080 x 5080 mm). 

Note that although the ISO PDF standard is explicit about the 14400 unit limit, some software vendors may choose to ignore it and create non-compliant documents. If your PDF viewer also ignores the standard, you will be able to view it. If your PDF viewer respects the standard, then results are likely to be blank page or a software crash.

 

Source: https://support.activepdf.com/support/solutions/articles/35000174586-how-to-determine-the-pdf-page-size