Weight issues between original file and copy

[Lucia284565667pes]

Hi, 

I'm doing graphic novel and I have a file with the thumbnails/sketches of each chapter in an inDesign file with the text added to it. I needed to do a copy of that original inDesign file to make a small change to do a proofcopy. But now the PDF that I exported from that copy is two times heavier than the original PDF. When I looked at the original inDesign file, it was 4MB, but the copy is now 6.3MB. There are no added images, no added text, I just changed the images for new ones, but the amount stayed the same, the images don't weight more than the originals and there's nothing else added to it, yet, the file is heavier. 

What could be happening? 
Thank you! 

[John Mensinger]

I just changed the images for new ones, but the amount stayed the same, the images don't weight more than the originals and there's nothing else added to it, yet, the file is heavier. 

Editing activity stacks bytes up over time, defying the "I-didn't-add-anything" logic you're applying. Are you truly certain you kept everything the same, or is that your assessment after the fact? There could be more image data out-of-frame, among other things. If that modest growth is a major concern, try exporting the file to IDML, then reopening to effectively "rebuild" it without retaining any waste.

[BobLevine]

I read this differently. The OP is, IMO, referring to the exported PDFs from two similar documents.

[John Mensinger]

Perhaps, but the only true specificity was here:

When I looked at the original inDesign file, it was 4MB, but the copy is now 6.3MB.

[BobLevine]

And then there's this:

"But now the PDF that I exported from that copy is two times heavier than the original PDF. "

In any event, I think we can agree there's no problem to solve.

[BobLevine]

You are concerned about absolutely nothing. There is absolutely no way to control the size of the exported PDF from one document to another. Nothing in your post sets off any alarm bells.

[Geоrge]

You can play with pdf export settings and find image compress settings in it