Exporting to epub creates huge file sizes

I started laying out my graphic novel in Apple Pages to export as an epub. I used reasonably sized images (I use Photoshop to reduce the image size and save for web resulting in about 1mb per image) The Pages file as well as a PDF file exports both came out at reasonable sizes. However, the exported fixed layout epub came out 6-10 times the PDF size! I gave up on pages and looked for other options.

Recently I came back to Apple Pages to see if there was some setting or method I was using that caused this. It turns out, I was doing something to create these large file sizes.

My original method was to place shapes down and insert my artwork/images into them. I did this as I liked the consistency and options available with using shapes as image frames. I also thought it was the best way to avoid resizing the image every time when placing it in.

I wondered if placing the images into the shapes could be the issue. I made a test where I placed the image files directly into the document, I ran a test epub export and the epub now exported even less than the PDF export file size.

To ensure I was consistently placing the images, I edited the 'page template' (View menu) and set up persistent guides. I then set up side by side windows (Pages & Finder) and just dragged in each page and resized to the guides. The resulting epub export came out pretty much equivalent to the original file sizes when combined.

I hope this helps someone out there.