Does expanding or vectorizing drop shadows actually decrease file size?

[tqrtuomo]

In my continuing quest to stay away from the Danger Zone (where Illustrator takes 2 minutes to save a file that's roughly 350 Mb in size, prompting Fear and Loathing that my Win10, 32Gb RAM system will hang), I'm looking at drop shadows. I use a lot of them in my maps, to make buildings stand out a bit.

As others have said over the years, drop shadows are rasterized, so it helps to decrease the Document Effects Settings to something like 18dpi (while the drawing is still in progress), just to help Illustrator render them quickly and save the file quickly. When it's time for the final, then you bump up the dpi to something more appropriate. Great.

But there's two other things to try that seemingly might help make things more efficient during the drawing-in-progress stage:

1. Expanding the drop shadows at the final desired dpi. Doing this, you deal with the rasterization pain just once, so Illustrator doesn't have to spend time re-rasterizing everything if you happen to make a change that triggers it. Seems to make sense. Wouldn't save file size, but should cut down on the time it takes to save the file.
2. Using a vectorized drop shadow, via some technique that can be readily Googled. Again, seems to make sense, as you skip the rasterization step entirely.

So I've tried both of these techniques on a simple group of shapes, and neither one has resulted in smaller file sizes or shorter save times. Which makes me wonder whether these are just Possibly Good Ideas That Don't Pan Out In Real Life, or perhaps whether I'm doing something mechanically wrong.

TIA

Tom

[Monika Gause · Accepted solution]

What slows down drop shadows is the rendering, which typically happens when opening the file, changing the zoom level, panning around or after editing.

What makes file size big is the incorporation of rasterized drop shadows in the PDF part of the file and of course after having expanded the shadow.

Additional slow down of the saving process happens with big complex files, saving on a server, compressing complex files and generally including the PDF part of the file.

[tqrtuomo]

Thanks very much, Monika. Sounds like expanding the drop shadow is a good idea just from the perspective of not forcing Illustrator to re-render it every time I zoom or pan. I won't expect the file size to change, though. Or, alternatively, I can just turn off the visibility on drop shadows, waiting until the final product to do those.

From your helpful YouTube video, I understand Illustrator files have a PDF component. Is this true even if the file is saved with the Create PDF Compatible File checkbox unchecked?

[Monika Gause]

If you uncheck that option, the PDF part doesn't get written. The file then only contains the AI part.