PDF file size unusually large.

Question

I've got a number of file size issues as of late. But in this case, I've made a rule book for a game that's 22 pages. Lots of precisely laid-out text, but plenty of symbol usage, vector art, and raster art.

Unfortunately, the resulting pdf was well over 1 GB.

I tried downsampeling as much as I could but it's still about 800 MB.

Large background images were reduced to 150 ppi and some other smaller items are reduced to 600 ppi.

I even made the large background into a symbol hoping that internal links would be used instead of making 22 copies of the thing, but Illustrator doesn't appear to work that way.

But here's the strange part. If I export the whole thing as a 600ppi png images, the total is about 100 MB. Where is the other 700 MB coming from?

This isn't the first time files have become crushingly large. Some are 2 GB across only 10 artboards. I do a lot of card-sized art (9 to a page) with elements using many symbols.

Saving a file takes a rather long time, and this is causing workflow issues, especially when it comes time to try and print. Or share. Or do anything.

Advice?

Ton Frederiks · Accepted Answer

Well I'm usually working directly in the pdf file so certainly editing is preserved.

I went through a bunch of the other files and found that a lot of the placed artwork was at inappropriate resolutions, including some buried hi-res images in symbols that just didn't need to be there. I fixed this, and the file sizes came down considerably.

I also tested saving a few as ai files, and there doesn't seem to be much size difference between the ai file and a pdf file.

At any rate, none of this helps the original file I posted about.

So I did some more testing.

Turns out, the pdf image compression is lying.

It says it's downsampling artwork to specific resolutions, but it's not.

When I downsample each placed artwork individually before saving, the file size comes down considerably.

Here's the problem. If you select downsampling AND preserve editing in illustrator, it doesn't downsample. (It will otherwise)

This might be classified as a bug.

Tychonoir wrote
Turns out, the pdf image compression is lying.
It says it's downsampling artwork to specific resolutions, but it's not.
When I downsample each placed artwork individually before saving, the file size comes down considerably.
Here's the problem. If you select downsampling AND preserve editing in illustrator, it doesn't downsample. (It will otherwise)
This might be classified as a bug.

If you select editing in Illustrator as an option, no lossy compression or downsampling will be applied to the Illustrator part of the file.

So resampling and compression is only used in the PDF part of the file.

Why do you edit as PDF? Use AI and save a copy as PDF without AI editing options.

Mylenium · Answer

I even made the large background into a symbol hoping that internal links would be used instead of making 22 copies of the thing, but Illustrator doesn't appear to work that way.

Symbols are an AI-internal thing. This has nothing to do with PDFs. Once you create a PDF, al lthe magic is gone. Conversely, actual image file sizes and so on don't matter in AI. It will still be resampled to the document DPI/ PPI. It seems you have some fundamental misunderstandings here. Resampling an image to 150 PPI in a 1200 PPI or so document will still turn out a huge document because of those things. I'm also not sure what you expect with regards to the difference of PNG vs. PDF. Again completely different things, since a print-ready PDF will do things such as embed its pixel data as uncompressed TIFF rather than a compressed format. hence it makes little sense to compare it to a PNG and its compression. The lengthy exports and saves no doubt are also related to AI is simply forever busy resampling your data to generate the previews and the final PDF. If you want better behavior you have to seriously read up and streamline your workflow accordingly.

Mylenium

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