File size reduction

[woodleigh]

Hi all

I've recently completed a design for a van wrap that I've sent to my signwriter so he can print and install, but he's software cannot handle the size, the file is 1.9GB after exporting it to pdf.

The design, a cherry blossom tree (attached) contains 1000+ individually placed blossoms. Each blossom started as an artist's watercolour sketches, that were scanned at high resolution.  I vectorised each blossom (there were about 10 different blossoms).  I then grouped them and linked them into the illustrator file.  The illustrator file I was working on was over 2GB, it was painful to open, save and close, let alone work with.
What was I doing wrong at this point?
Anyway, I now need to reduce the file size but maintain is scalability.  The illustrator file is at about 10% of the finished size for each side of the van.
(Attached is one side of the van.  The other side is almost identical, just the reverse layout.

My system
Macbook Pro
Chip - Apple M1 Max
Memory - 64 GB
macOS Tahoe 26.0.1

Your advice will be greatly appreciated.
Kind regards
Adam

[Ton Frederiks]

Did you try static symbols?

When an object is defined as a Static Symbol it is defined only once in the file when used multiple times.

Maybe you can use a script to replace the flowers (probably ungrouped) by static symbols.

https://github.com/alexander-ladygin/illustrator-scripts/blob/master/replaceItems.jsx

[woodleigh]

Thanks Ton.
That sounds like a great idea, however, I've never used scripts in illustrator files before, I wouldnt know where to start. 🙂

[Ton Frederiks]

Scripts are a wonderful addition to Illustrator and easy to use.

You can download (click on download the raw file)

or copy the script and paste it in a text only file (no formatting) and save it with the extension .js or .jsx

To use it put it in the Illustrator applications folder > Presets > your language folder (like en_GB) > Scripts

You may need to enter an admin password.

It will appear in File > Scripts...

The script may need an (ungrouped) selection with the symbol on top.

[Ton Frederiks]

See also for additional info:

https://helpx.adobe.com/illustrator/desktop/automate-visualize-data/automate-actions/install-and-run...

[woodleigh]

Thank you so much.  Looks like I'll be learning something new.  I'll let you know how I go.

If there are any other methods of reducing the file size, particularly one that is 2GB, I'm all ears.

[Ton Frederiks]

Yes, I am curious to hear about your experience. 

Using Symbols for repeating elements can reduce the filesize dramatically. Important is that the Symbols are Static instead of the unfortunate default Dynamic. I have an example file that goes from 69,8 MB to 206 KB with static symbols.

[Bobby Henderson]

Are the cherry blossom blooms complex in nature? Do they contain any raster-based effects? As small as the blossoms are in relation to the rest of the design they could be simple (not have a lot of detail adding up to lots of anchor points). With the file size being so huge it makes me wonder if any left over blossom pixel-based images or other stray elements are hiding in the design.

I was going to ask about raster effects settings, but it looks like the design is pretty much all vector.

[woodleigh]

Thanks Bobby, yeah the blossom blooms are quite complex.  Each group that contains about 10 small blossoms, weight 37mB.  Can you advise what the best way to reduce that size, it would hurt to simplify them a little to get that size down, which would then get the overall size down I suppose.

[Bobby Henderson]

In the big picture view of the design, is it necessary for those small cherry blossom blooms to have a lot of detail in them? Vehicle wraps are typically seen from a distance. Any fine details would have to be viewed up close on foot while the vehicle is parked.

If I was using Live Trace in Illustrator to create vector objects from the blooms I'd probably limit the number of colors and loosen the pixel tolerance settings a bit. Generally speaking, it isn't good to have vector objects that contain more than a couple thousand anchor points. Some printers and large format RIP applications may reject objects that have more than a certain amount of anchor points. That limit could be 2000, 5000 or somewhere in between.

There are many instances where I prefer hand-tracing clean vector paths over placed pixel-based images. If I'm tracing the shapes by hand I can choose where I want the anchor points placed and how many I need for the shape. I can choose what elements in the scanned image I want to trace and others I want to disregard. Auto-trace filters can't work in a subjective manner the way the human mind can. The auto-trace filters just notice the greatest amount of contrast and try to trace that. The filters can be really dumb because they don't understand the context of the image details.

[woodleigh]

You are correct Bobby, you'd think I would have learned that from billboard designs 🙂  I think I was a little busy at the time and hastily got this project started without my usual checks and balances and never really thought about the output at the end.

I just need to get to the finish line now so am testing lots of different options people have been sharing.

[Kurt Gold]

Auto-tracing your scanned templates may be one part of the issue as it certainly produces huge amounts of paths and anchor points in this case (based on the preview you posted).

If, for some reason, you can't take the scanned raster art as is, you may want to simplify the auto-traced cherry blossoms (Object menu > Path > Simplify). That may help a bit.

Another thing are your .pdf export settings. Can you clarify what you are using there?

And another excellent approach, of course, would be to provide a sample Illustrator file and post a public download link for inspection. So one can have a look at it and see what further slimming diets may be possible.

[woodleigh]

Cheers Kurt.  Yeah, I did auto-trace which I'll think about twice next time.  I've simplified the linked graphics which has reduced their size by about a third, there are 100's of them so its still a hefty file.
The original illustrator file was 2GB, its now half that size.  When I save it to pdf though, it seems to jump up a bit again.  Screenshot of settings attached.
Is a 1GB file too large to share?

[Kurt Gold]

Yes, I think a 1 GB file may be too large to share via the forum here.

But you could share it via some file sharing service like Google Drive or the like. Make sure to provide a public download link if you want to take that route.

[woodleigh]

Cool, I'll do that Kurt, I've linked the file below, I've also included the linked graphics separately. I'd be interested to see what you think.  The obvious mistake was at the outset when I auto-traced the artists watercolour illustrations, but time is not on my side now, so I'm working retrospectively. 
 https://drive.google.com/drive/folders/1l-hIswGPHoSOdIvEc83dOQ94mpso7a8C?usp=sharing 

[Ton Frederiks]

Hi Adam, a couple of remarks;

I noticed that you used linked files, which should reduce the filesize in an Illustrator document by just pointing to an external file. But that reduction is lost when the option "Create PDF Compatible File" is used during saving.

The option will cause the embedding of the linked files in the PDF part of the file.

Unchecking the option will reduce the filesize from 2,1 GB to 166,3 MB.

Something similar can be achieved with using Symbols.

When static Symbols are used, the files need to be embedded, but will only be saved once in the file and referenced as many times as needed. This will also work when saving the PDF part of the file or saving as PDF.

But you may also have gotten a good result without vectorizing the blossoms and use them as a high res image embedded as a static Symbol.