Why do you wish that the final image of a PDF should be a JPG? Be glad that it is remaining so.
The best practice is to link PDF/4 from any other application and also from InDesign. It keeps vectors as vectors and text as text. You really will not want to convert text to PNG! Keep it as text.
The size of the final PDF depends on many factors. If it is not for print, try to export as PDF (interactive) and compare the file size if it fits for you. My recommendation is to avoid PNG in an InDesign workflow and to avoid JPG if text or vectors are envolved.
jordantheperson wrote… The exported spec sheet PDFs are around 4MB and when opened, the linked PDFs are slow to load.…
do you mean "slow to load" if you open the exported PDF in Adobe Reader?
This could be due to the complexity of contents of the placed print production PDF.
Mostly vector information, large number of path points, I guess.
To reduce this you could render the print production PDF to pixels. Best use PhotoShop for this and place a JPEG file of the result in InDesign. Depending on what you like to show you could do it high-res or low-res. When exporting the whole layout to PDF do not downsample image size then so that details in your placed JPEG will be maintained. At the exact effective resolution you are wishing.
The OP said:
… I am creating spec sheets for emailing …
Performance is the main goal here, not fidelity.
Uwe, using linked PDF/X-4 does both, minimum file size with maximum quality. How big the final size is, depends only on the PDF export settings. I recommend to use here PDF (interactive) Export.
I suspected complex vector graphic in the placed PDF.
Exporting to PDF Interactive would not render the placed PDF/X-4 to pixels.
And that will show in screen redraw time when viewed in a PDF reader.
Unless some transparency reduction would happen.
But to enforce that with export to Interactive PDF is hard to achieve, I think.
The usual means of transparency reduction will not kick in.
This is likely the correct answer. I will need to rasterize the original art. That, in my opinion is not a great workflow but it is what it is.
Adobe, once again, is a disappointment.
do you need different resolution for your images?
Maybe highres 600 effective ppi images for your original art ( a mix of text, vector graphic and images) that comes with the placed PDF and a lowres 150 ppi for all other images?
Depending on the quality goal concerning the highres rendered ones, this could be achieved with some InDesign trickery and merged layers with Acrobat DC. Totally without rendering the placed PDFs with PhotoShop.
It requires an extra layer for the placed PDFs, transparent objects stacked on top of each PDF graphic, a custom transparency reduction setting for exporting PDF to print for this layer only and another export to PDF Interactive for all other layers. Merging both PDFs would be done in Acrobat DC with Acrobat's Layer functionality.