How to Modify Parent Pages in InDesign: Understanding Page Size and Orientation Limitations

[Roger Breton]

Just curious...
InDesign allows creating new Parent pages with custom page sizes and orientation but will not allow to modify those attributes once the Page page is created. 
My question may seem trivial but is it because it would be too complex (in code) to allow changing those geometric attributes once the Parent page exists? 
I understand changing the page size in Document Setup modifies the "base" Parent page automatically. 
I understand it would not make sense to allow changing the document size through the Parent page dialog because we have the Document Setup dialog to do that. 
Still, it's a question my students ask and I confess I don't have a good answer for them.

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[Abhishek Rao · Accepted solution]

Hi @Roger Breton,

Great question! Once a Parent page is created, InDesign doesn't allow you to modify its page size or orientation directly. This limitation exists because Parent pages serve as a template, and altering their dimensions after creation could lead to complex reflow and layout issues across the document.

However, if you need to change the size or orientation of a Parent page after it’s been created, please try this: 

1. Create a New Parent Page with the desired page size and orientation.
2. Apply the New Parent Page to the relevant document pages. To do this, simply drag the new Parent page onto the pages in the Pages panel.
3. You can manually copy and paste any existing elements from the old Parent page to the new one.

If you're making changes that affect the whole document (such as page size), you can do this globally via 'File > Document Setup' to modify the base layout.

I hope this helps clarify things for your students!

Best,
Abhishek

[rob day]

Hi @Roger Breton , You should be able to change the size of any existing Parent or regular page with the Pages tool:

Create a new Parent spread based on the A parent with new dimensions

Select the Pages Tool, and with the B-Parent active in the Pages Panel, Transform its Height

The edited B-Parent applied to Pages 2-3:

[Roger Breton]

Rob, using the Page tool is a good "hack", granted. I was hoping for something a little less "advanced" for my beginner students. Nevertheess, it's interesting to observe the page icons change sizes in the Page palette while resizing pages using the Page tool *with the liquid page option 'Base on the Parent' active*. Thank you for your suggestion.

[rob day]

using the Page tool is a good "hack", granted.

I don‘t think of it as a hack—I use it all the time for document resizing. The problem with resizing the document from Document Setup is the reference point is always centered. That might be OK for certain documents, but the Page tool lets me set any reference point.

So that‘s helpful in a case like this where I’m resizing to a smaller 5 x 7" and I want the left pages to be anchored to the upper left and the right pages to be anchored to the upper right. I can choose to resize either document pages or the Parent spreads: