Different file sizes when exporting to PDF

[Gigatronix Pete]

Showstand A (top image) is an Affinity file I created with the details as per on the attached image.
Affinity file size is 14.4Mb - Document set up 3435mm x 3000mm
When exported to PDF at 250dpi & 92% quality the PDF file size was around 30Mb ...which was Ok.

I then did a "Save as" & created a Showstand B Affinity file (Bottom image) ...so exactly the same to start with.
I then moved the images around, made some bigger, made some smaller etc  ...changed the size of the text & added a vector Gigatronix logo
Affinity file size is 20.3Mb & the Document set up 2930mm x 2440mm (so a bit smaller than image A)
When exported to PDF at 250dpi & 92% quality (exactly the same details as I used on Image A) the PDF file size was around 120Mb ...which was most definitely NOT Ok.

These are wall images for 2 different show stands & having done a "Save as" & not actually added any other media, I am at a loss to explain the massive difference in PDF export file size!

Can anyone help or offer advice?

 

[Hangman]

Hi @Gigatronix Pete,

Without seeing the physical Affinity files it's going to be tricky to diagnose, are you happy to upload both so we can take a look at what might be going on?

Could you in the meantime also confirm which particular PDF preset (or PDF Version) you're using so we can ensure we're working to the same criteria...

[Gigatronix Pete]

Hello @Hangman thanks for the quick reply
I have attached both Affinity files ...Showstand B is a bigger Affinity file now as I embedded some of the linked images to put on here.
I had tried linked some to see how much if reduced the PDF file size.

PDF info image also attached

 

Showstand A.afdesign Showstand B.afdesign

[Hangman]

Hi @Gigatronix Pete,

Both files you've kindly uploaded are pretty much the same, as in, they're both variations of Showstand B at 2,930 mm x 2,440 mm.

Showstand A had the elements linked rather than embedded. I don't know if that was intentional but if not could you perhaps upload Showstand A, the 3,435 mm x 3,000mm file otherwise I'm largely comparing like for like with effectively two Showcase B files which come in at around 127 Mb when exported to PDF.

[Gigatronix Pete]

On 9/27/2023 at 4:42 PM, Hangman said:

Hi @Gigatronix Pete,

Both files you've kindly uploaded are pretty much the same, as in, they're both variations of Showstand B at 2,930 mm x 2,440 mm.

Showstand A had the elements linked rather than embedded. I don't know if that was intentional but if not could you perhaps upload Showstand A, the 3,435 mm x 3,000mm file otherwise I'm largely comparing like for like with effectively two Showcase B files which come in at around 127 Mb when exported to PDF.

Hello @Hangman
Firstly I apologise profusely ...work has been really busy & our exhibiton season finished after this show so I've been doing other things & forgot completely about asking you.
If you're still ok to look for me I have attached the correct original Affinity file which exported to PDF today at 24Mb

Again thank you for your help & apologies for me being such a muppet!

Best regards

Pete

IBC2023-SideWall_Version2.afdesign

[Hangman]

Hi @Gigatronix Pete,

That's absolutely no problem at all, no need to apologise...

So, it turns out the issue is a corrupted layer in the IBC2023-SideWall_Version2.afdesign file. The layer in question is the Artistic Text layer, 12G SDI, 4K.

• Export the file with that layer visible and the exported PDF is 25.7 MB
• Export the file with that layer hidden and the exported PDF is 135.7 MB

Based on the dimensions of the Artwork and the graphics contained within, in particular, the 'Connectors' and 'Cables' the file size of 135.7 MB is far more realistic and it also makes sense relative to the exported file size for Showstand A and Showstand B.

I hope that helps even though it's the opposite of what you were hoping for regarding file size..

[lacerto]

Obsolete.

[Gigatronix Pete]

9 minutes ago, Hangman said:

Hi @Gigatronix Pete,

That's absolutely no problem at all, no need to apologise...

So, it turns out the issue is a corrupted layer in the IBC2023-SideWall_Version2.afdesign file. The layer in question is the Artistic Text layer, 12G SDI, 4K.

• Export the file with that layer visible and the exported PDF is 25.7 MB
• Export the file with that layer hidden and the exported PDF is 135.7 MB

Based on the dimensions of the Artwork and the graphics contained within, in particular, the 'Connectors' and 'Cables' the file size of 135.7 MB is far more realistic and it also makes sense relative to the exported file size for Showstand A and Showstand B.

I hope that helps even though it's the opposite of what you were hoping for regarding file size..

Hello again @Hangman  ...well that's a bit freaky!?  so one corrupted layer actually makes the file size 110Mb smaller?
Excuse my ignorance here but does that make any difference to the quality of the PDF at all?
Because if not, in theory I could just copy the corrupted layer to the other file & reduce the file size on that one too

[Gigatronix Pete]

13 minutes ago, lacerto said:

It is probably mostly a question of having many large raster images (plus effects that will get rasterized) using ineffective image compression (Affinity apps do not seem to analyze images in anyway so the compression rate is fixed and cannot vary dynamically). I tested this by opening the larger document in Designer and exporting from there using PDF/X-1a with default settings, which flattens transparencies. I then opened this file in Adobe Illustrator CS6 and Designer v2 and re-exported to PDF/X-1.

The size are were as follows (the bottommost is the one that was exported from .afdesign file from Designer v2, and the other two are the PDFs exported from Designer v2 and Illustrator CS6 using PDF/X-1a export method:

I had problems opening the large Designer-created files in Adobe Acrobat Pro 2020, which gave error messages related to drawing, lack of memory, etc. or simply just crashed. After some retries and closing and reopening the app, Adobe Acrobat could display the files. But I doubt that there might be issues with ripping if files of this size and complexity are processed.

I would try to simplify the job by rasterizing object already on the canvas. 

Hello @lacerto thanks for the reply
Do you use PDF/X-1a for any PDF that will be printed?  ...I was told to use PDF/X4 for anything CYMK?

When you say "I would try to simplify the job by rasterizing object already on the canvas"
Do you mean rasterising everything on the page before exporting?

[Hangman]

24 minutes ago, Gigatronix Pete said:

...well that's a bit freaky!?  so one corrupted layer actually makes the file size 110Mb smaller?

It's certainly an odd one I have to agree but weirdly as far as I can tell it's having no detrimental effect on the quality of the PDF though it may be a completely different story if the file was sent to a RIP for separating...

26 minutes ago, Gigatronix Pete said:

Because if not, in theory I could just copy the corrupted layer to the other file & reduce the file size on that one too

Technically you could but I'd strongly advise against doing that because you could suddenly find you have three corrupt files which you can no longer open.

[lacerto]

Obsolete.

[Hangman]

2 minutes ago, lacerto said:

Btw, I did not experience issues with the other file, so I opened it without making any changes, exported it to PDF/X-4 without issues and the file size was 25,084KB so a bit less than what you mentioned above.

Hi @lacerto,

Hide the Artistic Text layer, 12G SDI, 4K in that file and re-export it...

[Gigatronix Pete]

Just now, Hangman said:

It's certainly an odd one I have to agree but weirdly as far as I can tell it's having no detrimental effect on the quality of the PDF though it may be a completely different story if the file was sent to a RIP for separating...

Technically you could but I'd strongly advise against doing that because you could suddenly find you have three corrupt files which you can no longer open.

Yeah I guessed that it wouldn't be a good thing to do  ....thanks very much for you advice & help on this one

[Hangman]

14 minutes ago, Gigatronix Pete said:

Yeah I guessed that it wouldn't be a good thing to do  ....thanks very much for you advice & help on this one

No problem at all, glad we now know what is going on at least...

[lacerto]

Obsolete.

[Hangman]

1 hour ago, lacerto said:

I removed the whole layer, yet the size of the exported file was 216,058KB (PDF/X-4), so it is not the layer that is corrupt; it is some odd Affinity error. It is strange that it happens when making the file simpler (removing text), but not when not making any changes.

That's not what I'm seeing on macOS, if I either toggle the visibility of that layer off or delete that layer completely and export the file (PDF/X-4) 92% Quality, both come in at 135.7 MB...

I'd say it's definitely that layer causing the issue/corruption.

Out of interest, are you testing on Mac or Windows...

[lacerto]

Obsolete.

[loukash]

I've tried to replicate the issue by creating a 4×3 m showstand wall using similar objects – albeit not that many – with a blown up masked image and lots of layer effects that cause rasterizing.
I couldn't replicate it.

The afdesign file is 12.8 MB, export with text 37.4 MB, export without text 33.2 MB, export without layer effects only 10.9 MB (as expected). Same PDF/X-4 export settings as above.

Whereas IBC2023-SideWall_Version2.afdesign causes the same issues as reported above. My conclusion is that there must be something corrupt about the file structure.

[lacerto]

Obsolete.

[Gigatronix Pete]

15 hours ago, lacerto said:

My standard when using InDesign is using PDF (press ready) based (default) routine which uses PDF 1.4 so it does not flatten transparencies, but converts everything to CMYK. I used PDF/X-1 with this job mainly because it simplifies the export file by converting everything to CMYK, and also because PDF/X-4s that I exported from the original file caused bad rendering and memory issues in Adobe Acrobat Pro.

Yes, I mean rasterizing objects and effects as much as possible on the canvas, before exporting but keeping vectors as vectors. So saving a copy of the current file and then rasterizing part by part and exporting (or at least previewing, since the preview window shows realistically the file size as it appears to be doing pretty much the same that is done in actual export).

Btw, I did not experience issues with the other file, so I opened it without making any changes, exported it to PDF/X-4 without issues and the file size was 25,084KB so a bit less than what you mentioned above.

Cool   ...thanks for the info @lacerto

[Hangman]

8 hours ago, lacerto said:

I probably misunderstand something, but if you, too, get equally large export file size when you completely remove that layer, then how can the issue be related to that specific layer? I can also hide the both raster layers below, and when I export, still get about 70MB file size (and pretty long export time). Leaving all these layers visible gives me a 25MB file. To me that implies that there is something wrong with the file in general, or with the way Affinity processes the file's elements when exporting to PDF.

I exported both the IBC2023-SideWall_Version2.afdesign and Showstand A.afdesign layer by layer as PDF/X4 files using 92% Quality and 250 dpi rasterisation starting with just the graduated fill layer and then adding the same layer to each file to compare exported file sizes...

• So the first export is just the graduated fill layer
• The second export is the graduated fill layer plus the PCB Board
• The third export is the graduated fill layer, the PCB Board plus the Ellipse

and so on and these are the results...

The file grows in size comparably between the two files bearing in mind the difference in document dimensions. It's only when you hit the Text layer in the IBC2023-SideWall_Version2 file that you see the sudden drop in file size.

Whether it is just that one layer that is corrupt or that layer triggers something else I have no idea but the text layer certainly appears to be the trigger. I think it is just a happy coincidence that Designer is able to render the file and reopen it but equally, I don't know enough about how file corruption works to understand the reasons. The fact that Adobe Acrobat Pro cannot render it, and 64-bit Illustrator CS6 crashes when trying to open it suggests file corruption.

I assume, but don't know for sure that the difference in exported file sizes between Illustrator and Designer is down to the respective PDF Libraries both use, it suggests Illustrator's library is way more efficient than PDFlib but again, I have no idea how PDF processing works with either library.

[lacerto]

Obsolete.

[Gigatronix Pete]

13 minutes ago, lacerto said:

You're welcome! 

I forgot a thing that is important when working with large designs: Affinity apps will upsample images to the defined export DPI (in your case 250dpi) when exporting using PDF/X-1a (and in certain cases also when using PDF/X-3), but not when using PDF/X-4. They also do it for images that have been cropped by using Vector Crop tool (or manually masked), and in this case using the document DPI (which in your case was also 250).

Rasterizing on screen will use the defined document DPI so images may be upsampled (using Bilinear algorithm) if you rasterize on screen, which you probably would not like to have (since you often intentionally use low-res images in jobs like these that are viewed at long distance), so in that sense my advise above about rasterizing on canvas and flattening effects may actually just backfire and produce poorer results (blurred and bloated images). It much depends on details... 

Ha ha thanks again for the info  ...it's certainly very rarely straight forward doing this kind of thing is it?
I only found our recently that if a PDF viewer will only sometimes show 5 metres max

[lacerto]

Obsolete.

[Hangman]

2 hours ago, lacerto said:

It is possible that there is a technical flaw, but they might also be "just" memory issues. At times Acrobat Pro fails to render these kinds of files and shows an error message "Out of memory", and when closed and relaunched, might render properly.

Quite possibly, do you think that is a software issue or a machine issue ...

I just took a look at the exported IBC2023-SideWall_Version2 file in PackZView... both with and without that text layer. When it's included it appears that the entire file is rasterised as a single image, unlike when the text layer isn't included...

Does this tie up with what you're seeing?

No Text Layer Left | With Text Layer Right