Exporting a large AI file to PDF for a print job - running into issues

[Katelyn25929141amqi]

Firstly, please excuse my ignorance in such things I normally work mainly in Product Design but sometimes I get roped into the more Graphic end of things as I work for a small company. 

I've been tasked with creating a design file for an exhibition booth - 5 panels roughly 1x2 metres but was asked to provide the artwork as a PDF at 25% scale. I believe I've managed to get the Illustrator file set up correctly but the trouble now is the file appears to be too large to export to PDF (I have the High Quality Print preset selected just with added trim marks). I tried exporting individual artboards rather than the whole file in one go but that also is not working. The file contains a lot of high-res embedded images so I'm wondering if that could be an issue? And if so how do I optimise images so I can export to PDF but without losing their quality? Or is there something else I need to be doing/checking? Any help from any proper graphic designers would be greatly appreciated!

[Bobby Henderson · Accepted solution]

First, if you have multiple artboards I would recommend saving each individual art board as its own PDF file. That will cut down on the file size.

Next, what is the resolution level of the embedded images? Depending on the viewing distance the pixel-based imagery may not need to be very high in resolution. Pixel-based imagery on vehicle wraps can be in the range of 72ppi and still look sharp. Photos on printed billboard ads are often as low as 25ppi. If you're using something like 300ppi or greater that's probably going to be overkill unless viewers are getting up close to the printed panels and looking at them for extended amounts of time.

You should check with who is doing the print work, ask them what kind of RIP application is being used and create your PDF files based on what works best for that RIP. I often save PDF files out of Illustrator for large format printing just using the Illustrator Default PDF preset. Even with that preset you can modify things, such as resolution levels of embedded images.

[Lukas Engqvist]

If it is large scale and not intended to be read as a broschure you don't need to have the same resolution as print book/broschure/leaflet as also Bobby mentions. Start from a PDF-X setting and then change the resolution to 150ppi.

[Katelyn25929141amqi]

Thank you both, I lowered the ppi to 150 and used the PDF-X preset rather than High Quality Print and was able to export all 5 artboards into a single PDF file.