I am using Word 2016 in Windows 10 on this PC.
I have a Word file originally composed elsewhere. I edited it and added three 82mm wide graphics. The "do not compress images in file" is switched off so that images are compressed. The file size is 356KB.
I sent this file to a reviewer who made very minor edits and returned the document. It was 8711KB. It appears to have been edited and saved on a MAC as the reviewer saw the size and zipped the file. The zip file includes a MAC file.
The returned file has the "do not compress images in file" switched on. I switched that off and re-saved. The file size is now 8239KB - still 23 times the original file size.


What more can I switch off on my PC to get it back to the original size?
I have 100 papers to pass to 200 reviewers so this problem may appear again and I don't want to be passing large files around the world.

Nobody has solved this problem but I have improved the file size.
At the start of this story the file is a docx file and 356kb.
After the editing and increase in file size it was still a docx now 8711kb
I opened and Save As a .doc file. Size went down to 1699kb
Open and save again as a docx and file size is down to 1587kb

Since no-one here has seen the file or possesses full details of what edits were made, we can't really be expected to tell you what the problem is. If the original and edited files were the same docx file, compressing it on a Mac would have little to no effect. The mere fact that changing the file format from docx to doc reduced the file size tells us there was a significant loss of content not supported in the doc format. That's a pretty clear indication we haven't been given the full story.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

Paul, I would love to learn more from you. I have the situation described above and another with the same changes but not so large files. This is going to happen again as I get through my current process involving more than 200 people reviewing papers.
How do I send several megabytes of files to you.

You could upload the file to OneDrive, then post a link here. However, without access to the pre-review and post-review versions of the file, it would be impossible for anyone else to even start to figure out what's happened along the way.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

Ok, I hope this is the link: https://1drv.ms/f/s!Aj3Y_ibknUwKhVSczv1wiPS-xTGq

I have put three Word files there. Two are the problem already described. File 39 Floyd Review is as I sent it to a reviewer. 39 Floyd Reviewer 2a is as it came back - almost as I have tried to reduce it back to the initial size.

The file 52 Kennedy Review is the size I received from the author but it is six to eight times larger than any of the other 100+ word files that have come in from authors.

If there is a switch somewhere in these files that will reduce their size I will be very thankful.

The simple answer is that whoever produced the '39 Floyd Reviewer 2a' has replaced one of your images (Fig 1: Location of South Georgia Island), which was originally a 119KB jpg file, with an 8778KB tiff version of the same image.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

Apologies. I hope that was not me as the reviewer does not have access to that image. This prompted me to dig deeper to find exactly the file that was returned by the reviewer. I thought I had trashed it so went away back. All I have done now is to rename this file to 39 Floyd Review Returned (8711kb) and put it in Onedrive at https://1drv.ms/w/s!Aj3Y_ibknUwKhVVh3uxOyYipctx2 Compare this with the original I sent, which I am sure has not been modified, 39 Floyd Review (356kb). I do have a tiif and jpeg version of that figure so I have just tested by making a copy of this paper and putting in the tiff version. Save that and the file size is 342kb. So next I have taken the monster file and replaced the graphic in that with the tiff copy. I also found that "File/Options/Advanced/Do not compress images in file" had been ticked. It was unticked in the small file I sent out.
So, the image was certainly changed. There is evidence that the file was used on a MAC. I now see how to change it back again. Replacement of the image is necessary. Simply going into the oversize document and unticking the box and saving does not reduce the size.
I hope all this is helpful.

Anyone who has access to the file could extract the jpg image and replace it with a tiff version - and all you'd need for that is to open the jpg image in any image editor and save it in the tiff format before reinserting it into the document. Regardless, Word's document compare utility shows that the image was replaced, and digging into the file data is how I found the details of that change.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

Thanks for the quick reply. I apologised above for the possibility that I may have changed the image in the first big file I sent so the original big file is now there. If you have the time and patience to check/compare only the two files that should now be available to you.
My experience with getting images out of Word is that if they have been compressed, as this one was, in Word then the resulting extracted jpeg or tiff is quite small. In this case extracting that image from my original small Word file gets me an image 710 pixels wide and 137kb as a tiff.

With a docx or docm file, extraction of the original image can be done by changing the extension to .zip, then accessing what Windows then regards as a compressed folder - or using a utility like WinZip.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

Thanks. Some useful information there.