Can we export FLAT PDFs from InDesign like we can from Photoshop?

So I ran some more tests, including @rob day's suggestion to run the INDD file through IDML.

• The original 27-page INDD file size (although only 24 are good & exported) is 175MB.
• The IDML file it creates is 7MB.
• The INDD file created from that IDML file is 69MB (>100MB less than original INDD file).
• The PDF file exported from this new streamlined INDD using "Smallest File Size" preset is unfortunately still 45MB. This seems to be the floor for all PDFs exported with InDesign no matter how low the settings.

So while this did not fix the problem, my first question is : what happened to the >100MB of data that disappeared from the file by running it through IDML? Did it discard anything important, or just bloat? I noticed it reset the length (but only the length) of some "inner glow" effects I had on 2-3 containers. Is it safe for me to use this streamlined version going forward, hoping the "inner glow" length is the only thing it screwed up? (Might be more reassuring if it told me what it discarded.)

Having pretty much given up the idea of not having to go through Acrobat, I also tried :

• Exporting to PDF from InDesign UNCOMPRESSED, but downsampled from 600 to 300dpi (because I got an error when I tried leaving it at 600) resulting in a 530MB PDF.
• Opening the 300dpi UNCOMPRESSED PDF in Acrobat and re-saving with "Reduce File Size" checked produced a 6MB file <- Victory!

Not only did it work, the end result looks even better than the 45MB PDFs produced by InDesign alone, no matter how low the settings are. But what did checking that box actually DO? Did it just apply the "Standard" PDF Optimization settings we can find under that section in Acrobat DC? In other words, 150dpi + Medium image qual.?

This confirms my InDesign settings (which were 100dpi and Low image qual.) should've gotten this thing down to 2-3MB, so there's still appx. 43MB of bloat being exported from InDesign no matter how optimized those settings are.

Auditing already revealed that 98% of the filesize is the images. Anyone have any last ideas to try before I simply accept Acrobat DC into the PDF creation workflow? (Not a big deal by any means, just means exporting the same mag twice from 2 diff. programs each time.)

PS: @Scott Falkner 9x12" (images are 600dpi sRGB files, but it was always the plan to export at 100-150dpi and adjust image quality settings to produce a decent PDF file size). Nothing really special beyond that (no special media or interactivity of any kind.. not even a hyperlink anywhere).

For accuracy, I still take my proof to Photoshop to flatten especially for complex PDFs. It's safer. period.

@LaubenderI followed your instructions (thanks for the step-by-step, as I'm a bit out of my depth) and found that 98% of this magazine's weight is from the images. In other words, I was wrong to assume that keeping the text as type might have been partly responsible for the size. What I don't understand, however, is that I tried literally everything to get this filesize down. All the PDF-X formats, reducing DPI to 90, lowering image quality to LOW... nothing gets this thing under 45MB. In fact, all these changes only made it fluctuate by 1 or 2 MB in either direction.

I'm guessing there's something I need to do to my layers before the export. I just assumed all the photos (which are links to PSDs in a separate folder) would be flattened and reduced at the export, but it doesn't appear to be behaving that way. Is there no simple way to just tell InDesign "flatten all pixel (photo) layers to one, crop out everything exceeding the visible canvas, and save" like you can when exporting PDFs from Photoshop?

@BobLevineThe main reason was to get the filesize down (as a test) and then I got hung up on the fact that InDesign just can't do it. Turns out you were right, I was looking in the wrong place, the issue is 100% the images.

@Test Screen NameYou're 100% right in most cases, but because in some rare instances I've seen the size of pamphlets reduce by flattening the entire document (and losing the vector data) I was hung up on trying it here. Mostly because I tried everything else 2x each. But Acrobat revealed it was the images all along.

@Eugene TysonThat was going to be my next step, until I learned 98% of the document is the images, so the type isn't at fault.

The type for the entire book barely takes up 1 MB, meaning (if I understand correctly) I should be able to reduce this document to 2-3MB in size if I'm willing to sacrifice ALL the image quality. But I can't get it under 45MB, even with all those DPI and image quality settings at ridiculously low settings.

So what else could it be?
I'm pretty sure I can just export the mag with NO compression and have Acrobat take it from there... but I'm trying to simplify the workflow, and I'm still learning InDesign. Shouldn't I be able to get this thing under 45MB without using other software? Most True PDF magazines out there are about 10-15MB at 110dpi (on average) with more pages than this one. I should be able to get it down to that size, right?

PS: The PSDs being linked to are 600dpi and set to the same physical dimensions as the space they're filling on the page (the idea was always to lower the DPI at the export). They all have adjustment layers and FX, and some have hidden layers, but only if those hidden layers are potentially useful. Because this is mainly for online usage, I've assigned the sRGB color profile to both the ID file and the dependent PSD's. ID's Transparency Blend Space has also been set to RGB.

Hi @Under S. A page containing any transparent object, exported to PDF 1.3 Compatibility will use the Transparency Flattener Preset set in the Export>Advanced tab—create a Flattener preset that forces the entire page to rasters. You can place the transparent object in the bleed or slug of your master pages. So:

To answer your question directly, you can't rasterize text when exporting to PDF without jumping through a whole bunch of flattening tricks so I've gotta ask...

Why do you want to do this?

Hi @Under S. ,

if your concern is file size, export the document to PDF/X-4 and open the PDF with Acrobat Pro DC.

Check what exactly is responsible for the file size.

When in Acrobat Pro DC: Tools > Optimize PDF > Advanced Optimization > Audit space usage…

Best do a screenshot of the Audit Space Usage and post it here.

Thanks,
Uwe Laubender
( Adobe Community Expert )

The only way I see, export as PDF/X-4. Open that in Photoshop and save it there in JPG. 

If text is selectable, it is only because Acrobat is trying to do an OCR with Font recognition.