Hello, Jacob Norris here. I've had this important tip out on a few locations over the years such as blogs or PDF downloads. However, I like this tip to follow me wherever I go because it is an important part of designing large layouts. So, since I'm now with the fantastic team at Footprint Exhibits and FPPortable, it's time to get this information online again so you can benefit. Here we go.

Can you make a 1 or 2 Gigabyte file easier to work with? YES!

When using Adobe Illustrator for your large format graphic design, these tips and suggestions will help you make smaller files that will increase your productivity. Illustrator is my preferred program for finalizing layouts that will be printed to extreme dimensions (mixed with pre-prepared raster elements in Photoshop). You may prefer to work in Photoshop exclusively (and sometimes InDesign, though not recommended). However, these tips just focus on Illustrator.

So, with that said, here are 4 Tips to use when designing large format graphics in Adobe Illustrator...

Illustrator Tip 1 – Always work at 100% scale if possible

This tip may seem odd at first. Some designers feel that a file prepared to 200" wide by 96" tall will be huge just because of the dimensions instead of scaling it down 50% or 25%. But generally an Illustrator file should not greatly increase in file size regardless of art-board dimensions when you follow this tip plus the ones below.

Working at 100% scale has many benefits. When placing raster files into your layout you won't have to scale them down. Rather, you can pre-set the dims in Photoshop to what they should be and just position them as needed. You also don't have to worry about any outline point sizes or effects not scaling up properly when at the printer because everything will be set to what it is intended for.

If the project you are designing for has dimensions larger than what Illustrator art board limits permit, you can then drop in scale. I recommend selecting easy to calculate reductions, such as 50% or 25%. Be sure to let your printer/vendor know what percentage you used when sending your final files.

Illustrator Tip 2 - Always "link" your placed raster images rather than "embedding" them.

Linking images in IllustratorAdobe Illustrator can "link" files in the same manner that InDesign or Quark does. Meaning, the raster image isn't permanently inside the file itself but is instead referenced from a different folder location (the links folder) on your drive. This ensures your Illustrator file size only is made up of the vector elements and raster effects applied, not the huge raster images themselves.

If you save an Illustrator file with "embedded images" you are increasing the file size to include the sizes of those images as well as the Illustrator native elements. Opening a file that has images embedded will be slower to process and can also cause your video card to eventually max out and generate errors on the screen.

As referenced in the EXAMPLE 1 IMAGE (click for larger view), you should always have the "link" check box marked when placing images into your layout.

Illustrator Tip 3 – Verify that no images are "embedded" in your layout.

Images that are linked or embedded in your Illustrator layout will appear differently in the links palette. This makes it easy to identify if you have an image embedded and also then provides you the awareness to "un-embed" the image for a smoother work flow.

Do not embed images in IllustratorSee the example image. As indicated, the first image has been "embedded" but the second image is linked.

When you see an embedded image, you have a few options to correct this. First, if you already have the original image on your drive, you can click that image and select "re-link" from the menu in the links palette. Then, locate the original file and choose to "link" it.

But, if you don't have the original raster image any longer on your drive, you can then select the option to "un-embed" the file. This will create a new raster file on your drive, generally in PSD format that you would rename, but sometimes as the original file format and name.

Either way, be sure to get your files linked and then re-save your Illustrator document. It's getting smaller.

Illustrator Tip 4 – When saving your Illustrator file, ALWAYS "un-check" the boxes that say “Create PDF Compatible File” and “Include Linked Files”.

Verify illustrator save as settingsThe default setting for saving files in Adobe Illustrator is to have "PDF Compatibility" turned on. Adobe does this to ensure that various versions of Illustrator will still be able to open the file for the most part even if you are not using the latest edition of Illustrator. However, this is a wasteful setting that only increases the file size and it should be negated every time you save unless you also need the file to be opened in Photoshop for other design elements.

Reputable printers are always up to date in their Adobe Suite software. So, having this option as part of your file save is just wasted space. Since we would be asking you for the Illustrator file and the linked images, the PDF option isn't necessary.

Also, the "include linked files" option when saving a file should never be selected. This would end up embedding your raster files into the layout. And, as noted in the tips above, that will only increase the file size.

Finally, be sure to always check the box that says "Use Compression". This reduces your file size even further.

Example of the above tips in action.

Let's now use an actual example to illustrate these steps so we can see how much a file size can be reduced.

A layout I worked on in the past month for a basic 94.5" x 94.5" backlit graphic required 14 raster images inside an Illustrator layout prepared to actual dimensions at 100% scale with template bleed.

If the file was saved with all images embedded, PDF compatibility turned on, and compression turned off, the resulting document was 234 MB in size.

However, if the same file was saved with all raster images linked, PDF compatibility turned off, and compression turned on, the result was the following:

Illustrator file size: 483 KB
14 Linked Raster Files total size: 26.8 MB

TOTAL SIZE OF FILES: 27.3 MB

That is almost a 90% reduction in size for the material!

Imagine the reduction you can make on files of much larger size when working on large format graphic layouts!

Beyond these tips, here are some other items to consider when working on large format layouts in Illustrator...

  • Don't save raster images in EPS format if your output is going to be Inkjet, Dye Sublimation or Lambda. EPS raster files are best used when printing for offset applications. Duotones, Pantones and so on are excellent examples of when a raster EPS file is necessary. However, in large format, you are only printing in CMYK and some features of an EPS raster image may cause issues and require manipulation by the press operator or your vendor. If you are billed for those services and modifications, this may mean your budget is now out of balance. Rather, save raster images in Level 12 JPG from Photoshop, or as uncompressed TIF files or PSD images. Not sure? Consult your vendor before saving.
  • If you are working with an EPS file that is 100% vector objects, make that object part of your layout instead of linking it in Illustrator. A linked vector object can actually cause issues if there are problems in the original file. I've seen EPS files with fonts not converted to outlines, missing linked raster images or low quality images, and incorrect colors. Therefore, bringing the file into your layout will ensure you have already corrected any errors. 
  • Always convert fonts to outlines before sending a file to your press or vendor. It's a common request in the large format world and you should follow it. Just be sure to review every single inch of your layout after converting a font to outlines so you confirm all objects are still in position. I've seen many fonts lose items after the conversion.
  • And as a last note, never send PNG files with your layout as raster images. The PNG format does not support CMYK color profiles. Therefore, it will need to be converted at the press to a different format before it can be printed. Again, this may cause you increased fees. The same goes for GIF images. NEVER!
Now, keep in mind that your print supplier may have graphic requirements that are not a match to these recommendations. If that is the case, ignore everything I've said and follow their instructions. In the end, your supplier has a print method that is working for them. But, I would recommend caution if their requirements do not accept files that match these tips. 

Need more information or have Illustrator questions? Feel free to reach out to me at Footprint Exhibits. I'm always happy to talk shop.

Jacob Norris