Huge file size variations for both afpub and pdf files

[waltonmendelson]

Summary

The same afpub files, on average101MB, saved after correcting a few typos (literally) can vary in size by more than 50%. PDFs made from those file can vary in size by almost 70%.  I have examined these files, and they appear the same. With the PDFs, Preflighting and checking colors with the Output Previewer show nothing to be different amongst the files.

Details

My system runs Windows 10 (it is up to date); 32 GB of RAM, and I am running Affinity Publisher, ver 1.9.2.1035.

I am making two illustrated 80-page books, approximately 1,000 words. They are identical except for two words. These are test books, intended to test print quality for color and B&W images on standard and premium papers, using Kindle Direct Publishing: hence the difference in words: “standard” in one, and “premium” in the other. 

Because I’m testing images and print quality, the files use CMYK, RGB, and device gray (therefore, PDF/X-3).  The resolution ranges from 300ppi to 4800ppi (therefore, Use document resolution).

My workflow is to develop and correct one file, then save it as the other. I Export both files to PDF:

• PDF/X-3 
• All pages 
• Use document resolution 
• Allow JPEG compression: 100%   

I noticed the file sizes vary considerably within each iteration (fixing typos, etc.), the images do not change:

• Affinity Publisher afpub files range from 66MB to 122.6MB. 101-102MB are the most common, and presumably the “good” size.
• PDFs, all using the settings listed above, range from 101.6MB to 150.9MB. 115MB is the most common, and presumably the “good” size.

Yesterday I ran a comparison of two PDFs, one at 101.6MB the other 115.2MB (both made from the same iteration of the same afpub.  Acrobat found 41 difference aside from the two words, all were were for images indicating the source had changed: obviously this is nonsense, so Acrobat's Compare Files is of no help.

Some variation in file size I expect, but not 50%.

Today I set out to see if these variations were caused by working on files throughout the day, where resources diminish and heat builds up.  So first thing:

• Created a new Standard afpub file
  • File size 102.062MB 
• Exported it to PDF/X-3
  • File size 115.217MB

Immediately after:

• Saved the Standard afpub as Premium, changed the words Standard to Premium   
  • File size 101.579MB  
• Exported it to PDF/X-3  
  • File size 150.987MB

Conclusion

• It is impossible to accept a file without confirming that it's size is where it should be (maybe), or if that even matters    
• There is no way to know whether size variations are due to material/information being lost or whether there is some kind of bloat
• It is impossible to use AffinityPublisher for designing and formatting clients' books 
  • creating multiple files to assess file size is too time consuming (the books here are mine, so it's my time and I don't have to charge anyone for it)
  • unless there is a good answer or fix, the uncertainty of producing files that are problematic is too great a risk when there are alternative programs, like InDesign, which, although not without huge potential problems, is more reliable regarding producing good, print-ready PDFs. 

Walton

 

 

[waltonmendelson]

I should have added, "Each book will be printed on a different paper, therefore I need a different PDF."

Walton

[Pauls]

Could you upload the project as a package here please so I can investigate.

are you changing any settings for the different PDF's e.g. Colour profiles ?

[waltonmendelson]

I should have added, "Each book will be printed on a different paper, therefore I need a different PDF."

Walton

[waltonmendelson]

To Pauls . . . Thank you!

[waltonmendelson]

Pauls . . . I forgot to answer your question, are you changing any settings for the different PDF's e.g. Colour profiles ?

KDP (Kindle Direct Publishing, a division of Amazon) will strip off our profiles, which makes sense given what gets uploaded there. We have no idea what profiles they would prefer.  Secrecy is one of the Amazon hallmarks.

I do not change the profiles from one book to the other.  The two books are test books, where one book is to be printed on "premium" stock and the other on "standard" stock.  I want all other variables--profiles, for example--to be the same.

Walton

[Pauls]

So far I've been getting very consistent PDF sizes. Could you upload 2 of the PDFs which should be the same but are of different size

[waltonmendelson]

Related to this problem in Publisher:

I was answering a question on the KDP forum, which had to do with image formats for print PDFs, specifically PNG vs JPG.  Using Affinity Photo, I took a JPG image, converted it to PNG.  JPG, 2.2MB, and PNG 13.3MB.  Then I converted/exported each to PDF/X-3:

• PNG to PDF/X-3 . . . 18.3MB
• JPG to PDF/X-3 . . . 115.7MB
• JPG to PDF/X-3 . . . 115.7MB
• JPG to PDF/X-3 . . .    5.7MB in Photoshop   

 Walton

[waltonmendelson]

Again, the difference between 6MB and 113MB is a tad big.  I do not know what makes up that bloat.  I do work that is intended for print.  Many printers have their own PDF presets; however much of my work is printed by Amazon/KDP, and everything about what they do and how, is a secret. I have no idea how the bloat will effect printing.  

Here is the same picture (you'll see that at 12% magnification it is the same dimensions), however you'll also see the file sizes are not the same!

I assume you use the same conversion engine in Publisher and Photo.  The only difference regarding this problem from what I posted originally is that in Publisher the afpub file itself could also vary in size quite a bit. 

 

[waltonmendelson]

Sorry, I did not change the caption.

[agc]

I have similar problem, see topic  ".afpub file size", my output pdf also vary but thought just deal with one issue at a time. No clear answers tho.

[waltonmendelson]

Here is why this problem is so unacceptable:

I have a book, mostly images, to upload to KDP.  The PDF have been in the neighborhood of 113MB.  I was about to upload corrected files, when I saw that they are 235MB.

I cannot up load these files.  Over 100MB of ______________!?  

I cannot risk the printability of the file. 

 

[waltonmendelson]

After 6 reboots, and 6 times opening and saving the afpub files (several comments have suggested that afpub files get bloaty and will purge unnecessary crud):

afpub files (these are identical files except for the titles):

• 131MB 
• 182MB
• 195MB

PDF (PDF/X-3 modified to not downsize):

• 240MB
• 240MB
• 240MB

Just to clarify, I am actually doing 3 books, all identical except for the titles and how they are to be printed.  The PDFs should be in the neighborhood of 149MB, based on the the previous PDFs.

This is several months of work.  Is it useable!?  Yes, they are fully PDF/X-3 compliant, but they appear to have almost 100MB of bloat.