@arrghh You would be better to actually design a Custom Page in the BOOK Module to then create JPGs or a PDF.
The one limitation is that you are limited to the provided default Page SIZES as given in the Book Settings panel.*
a) Design a Custom Page Template (in the book module). Adding cells, re-arranging, re-sizing, etc, on the page.
b) Save as a Custom Page Template. (EDIT: Note- Custom Page templates are specific to the Page Size selected! )
c) Create (Edit) an Auto-Layout Preset- using your Custom Template
Now to create the JPGs or a PDF
1) Set the Book Settings > Book to [JPG] or [PDF]
2) Select a Size, eg. Standard Portrait
3) Set JPG or PDF attributes- Quality, Profile sRGB, Resolution PPI, Sharpening, Media.
4) Choose your saved Auto-Layout Preset in the Auto Layout panel.
5) Click the [Auto Layout] button.
Your book will auto fill with all the images on the filmstrip creating as many pages (all with the Custom Page) as required.
Hint: Have images pre-sorted (in a Collection) as you want them on the book pages (it lessens later re-arranging)
6) Click on the button [Export Book to JPG] or the [Export Book to PDF]
*If you [Export to JPG] you do have the ability to use Photoshop to crop the JPGs to an exact ratio if the default Page size templates are not exactly what you want.
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