After changing the Canvas size (not artboard), saving and compressing a PDF makes all images blurry

[Extruflex UK Marketing]

Hi

TLDR: After changing the Canvas size (not artboard), saving and compressing a PDF makes all images blurry while the file size is still rather large. It was able to be compressed better before changing the canvas size.

I have been working on a huge brochure for a client and have been using Illustrator. I started to run out of space on my Illustrator workspace (Canvas) and had to create a new Illustrator file to increase the canvas size.

I transferred all my artboards (by copying and pasting the artboards) across to the new file and it seemed to be working fine while working on it. The only issue is when I save the file as a PDF and add compression, it becomes extremely blurry while still having a rather large file size (100's of megabytes). Here's an example below:

 

Before transferring the files to this new and larger Canvas size, the compression worked well and the images kept their quality. I've even tried saving the images as an uncompressed PDF and used a different compression tool but have found that this also makes the images extremely blurry and pixelated. This method seems to work on my older file before changing the Canvas size, so I am convinced it must be this change to the new Canvas size that is causing the issue.

My goal is to create a decent-quality editable PDF that is compressed but is still decent quality while working on a larger canvas size. We want to be able to compress the file like it did before changing to the new Canvas size. Is there a way to do this without these compression issues? Has anyone else had this issue?

[Monika Gause]

Please do that kind of work in InDesign. Illustrator is not made for this.

If this happens after compression, then possible just don't compress?

[Extruflex UK Marketing]

Unfortunately the file size is huge and will need to be compressed... I'll have to look at alternative options. Thanks for the help

[Ton Frederiks · Accepted solution]

If I set the Downsample resolution to 2400 ppi in the compression settings (which is the largest I can set), you will end up with 240 ppi  in the PDF.

Ilustrator is doing some scale tricks (10X) to create these large canvas files.

Or try multiple normal canvas size Illustrator files.

And indeed, InDesign was made for this kind of work.

[Extruflex UK Marketing]

I think this will have to be the solution going forward. I'll have to try to create multiple normal canvas sized Illustrator files and merge them together. I had a feeling there was some weird scaling trick going on. Thanks for the help!

[Ton Frederiks]

You may want to vote here:

https://illustrator.uservoice.com/forums/601447-illustrator-desktop-bugs/suggestions/47439314-pdf-fi...