I have had this issue for over a year now. I do a lot of "treatments" for photo clients. Basically indesign docs of full spread images with a little type here and there, exported as PDFs. When I make these it is always easy to export them and get the pdf file size somewhere around or under 12mb with some compression and color space adjustment.... UNLESS! Unless the imagery I'm using is black and white! Its not greyscale, its an RGB image but with black and white adjustment from lightroom and then exported as a tiff or jpg. If I were to make two identical indesign files and export two pdfs with the exact same settings, one with color RGB images and one with black and white RGB images one, the color would read 13mb and the black and white would read 85mb. WHAT AM I DOING WRONG HERE?? My only poor solution so far is exporting a pdf and then running it thought acrobat to downsize it again, just to get the file slightly smaller but its still usually well over 12mb. PLEASE HELP
Copy link to clipboard
What settings are you using when creating the PDF? Are you using PDF/x-4:2010?
Yes I’ve tried that export setting. As well as “smallest possible file” and custom settings, where I downsize to 72dpi and set the quality to “low”. I’ve tried converting the color space, keeping the profile, discarding the profile, setting to to CMYK, sRGB. I swear I’ve tried everything.
I tried exporting to PDF from InDesign with just one image, one color and one RGB black and white. The PDF with the black and white image was slightly larger, only half a percent larger, no where near the huge difference that you are seeing.
Does this happen with all files or just one?
It happens everytime I make a pdf with black and white images. Ive never tried just one image... but with over 10 full spread images i guess that starts to add up?
I don't think it shouldn't be adding up to anywhere near that much difference, even with 10 full page spreads.
If you're able to upload an example PDF with color and without color I'll take a look at them.
Copy link to clipboard
I am confused of your description.
The correct way would be with complete B&W imagery: Save images as Greyscale and export them as CMYK with Convert to CMYK with keep numbers to avoid converting them to 4c images.
The file size is given by the size in pixels and the embedded output color profile.
You can also use a greyscale output profile in your case if the font has no other color neither. 12mb would not be so extraordinary large if it is a print file.