How to use different page sizes in one document
Use the Page tool in Layout by Zaweba to give pages their own size and orientation in one document, with presets from ISO A to business cards and screens.

Each page in a Layout by Zaweba document can have its own size and orientation. Select the page with the Page tool and set a new size, either a custom one or a preset from the list, which covers ISO A, B and C, US sizes, DL, business cards, social media and screen sizes. The rest of the document stays as it was.
Plenty of jobs need this. A stationery set has a letterhead, a compliments slip and a business card. A brochure might have a fold out map. A report could have a landscape page for one wide table. Keeping them in one file means one set of swatches, one set of styles and one export.
Why one document beats several
When related pieces live in separate files, they drift. A brand colour gets tweaked in the letterhead but not the business card, or a font is updated in one place and forgotten in another. In one Layout document, global colours update everywhere they're used, and paragraph and character styles keep type consistent across every page size.
It also makes handing over easier. One file to check, one preflight, one package for the printer.
Step by step with the Page tool
Start with the size most of the document uses. Add the pages you need in the Pages panel, which shows each spread with page thumbnails. Then choose the Page tool, click the page that needs to be different and pick its new size from the presets or type in custom dimensions. Change its orientation in the same place if it should be landscape.
The page changes size and the rest of the document carries on as before. In the Pages panel you'll see the odd one out at its own shape.
Pages in spreads
Spreads can hold from 1 to 10 pages side by side, and pages in a spread are joined at their shared edges. That's what makes a gatefold possible: a spread where the flap pages are a little narrower than the centre ones. If you change the size of one page in a facing spread, think about how it will fold and bind.
Layout tips for mixed sizes
Plan your parent pages. Guides can live on parent pages, so a business card size and a letterhead size can each have their own margins and column guides. Give each size its own parent page so you don't keep fighting guides that belong to another shape.
Use the Navigator panel and zoom to page when moving between very different sizes. A business card next to an A4 letterhead is tiny, and zooming to the page you're working on saves a lot of squinting.
Set bleed thoughtfully. Bleed is set per edge and can be zero on any edge. Small pieces such as business cards usually need the same bleed as larger ones, so check with your printer.
Exporting a mixed document
A PDF from Layout keeps each page at its own size, which is what a print shop expects for a stationery set. If the printer wants each item separately, export the pages you need one at a time, or use File > Output jobs to save named sets of exports with naming patterns so it's one click next time. Picture exports (PNG, JPEG and TIFF) work per page or spread too, handy for social media sizes made alongside print pieces.
Live preflight checks every page, whatever its size, for missing fonts and pictures, low resolution and bleed problems.
When separate documents are still better
Very long jobs, like a book, are better as a set of chapter documents joined into a book in Layout, with running page numbers and synchronised styles. Mixed page sizes suit families of related pieces rather than a 300 page novel.
For everything from a stationery set to a report with one landscape table, Layout by Zaweba keeps the sizes together in one file.