I want to use Apple print to print a square book - using Aperture. How?

I want to use Apple print to print a SQUARE format book - using Aperture. How?

Not with Aperture. You have to use the new Photos for Mac, if you want to print a square book with Apple's Print services.

You could collect the images you want in the book in an album, export the albums a s a new Aperture library, open the album Photos, and create your book.

Or create a custom book in aperture, print the pages of the book to JPEG, import the jpegs to Photos and use them as full page photos to create a photo book in Photos.